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Computer Science - Kendriya Vidyalaya NDA Khadakwasala, Pune

1. else cout lt lt Year lt lt year lt lt is not a leap year else cout lt lt Year lt lt year lt lt is a leap year cout lt lt Year lt lt year lt lt is not a leap year end of main The above program is a very good example showing the use of nesting of if Explanation Let us first understand which year would be called leap year a leap is a year which i is divisible by 4 but not divisible by 100 ii is divisible by 4 as well as divisible by 100 and at the same time divisible by 400 Any other criteria will make the year as a non leap year candidate Dry Run 1 Let us parse the gray area code of the above program with a dry run having year 1994 if 1994 4 0 gt jf 2 0 gt if false Since the first if condition is not satisfied the flow of the program proceeds to its else block and prints the output as Year 1994 is not a leap year Dry Run 2 Let us parse the gray area code of the above program with a dry run having year 2000 if 2000 4 0 gt if 0 0 gt if true Since the first condition evaluates out to be true it opens up its block and the next statement in the inner block gets executed as gt if 2000 100 0 gt jf 0 0 gt if true Since the first nested if condition evaluates out to be true it opens up its block and the next statement in the
2. Ans 19 18 What will be the output of following code void main Int j 5 k k a a a cout lt lt k Ans 18 Because in evaluation of expression first of all prefix are evaluated then it s value is assigned to all occurrences of variable Unit 3 PROGRAMMING METHODOLOGY Algorithms and Flowcharts After studying this lesson the students will be able to understand the need of Algorithm and Flowcharts solve problems by using algorithms and flowcharts get clear idea about sequential selection and iteration construct and understand the finite and infinite loop Introduction Algorithm is a step by step process of solving a well defined computational problem In practice in order to solve any complex real life problems first we have to define the problem and then design algorithm to solve it Writing and executing a simple program may be easy however for executing a bigger one each part of the program must be well organized In short algorithms are used to simplify the program implementation The next step is making the flowchart It is a type of diagram that represents an algorithm or process showing the steps as boxes of various kinds and their order by connecting them with arrows Then the flowchart will be converted into program code Algorithm An algorithm is an effective method expressed as a finite list of well defined instructions for calculating a function starting from an initial state a
3. cin gt gt my_art i J stores value at i index program 4 3 I program to store 10 integers and show them include lt iostream h gt main int my_arr 5 name of array 119 cout lt lt nEnter values at for int i 0 i lt 10 i cout lt lt n lt lt j 1 lt lt cin gt gt my_arr i stores value at i index for int i 0 i lt 10 i cout lt lt Number at lt lt i 1 lt lt lt lt my_arr i show value at i index program 4 4 program to search a particular value out of linear array include lt iostream h gt include lt stdio h gt include lt process h gt main int a 10 val 0 cout lt lt Input ten integers inputting array value for int i 0 i lt 9 i cin gt gt afi searching element for int i 0 i lt 9 i if a i val cout lt lt Element found at index location lt lt i getch exit if element is found no need to further search terminate program II if control flow reaches here that means if in the loop was never satisfied cout lt lt Element not found Il program 4 5 I program to find the maximum and minimum of an array include lt iostream h gt main int arr 10 6 9 17 34 20 34 2 92 22 int max min arr 0 for int i 0 i lt 9 i if arr i lt min min arr i if arr i gt max max
4. math h Q No 4 a What will be the output of the following program int main int i 0 x 0 for i 1 i lt 10 i 2 cout lt lt x cout lt lt n lt lt x b Rewrite the following program after removing the syntactical error s if any Underline each correction include lt iostream h gt int main struct movie char movie_name 20 char movie_type int ticket_cost 100 movie gets movie_name gets movie_type A include lt iostream h gt include lt stdio h gt void main struct movie char movie_name 20 char movie_type int ticket_cost Movie Movie ticket_cost 100 gets Movie movie_name cin gt gt Movie movie_type c Define the terms Polymorphism amp Inheritance d Write the output of the following program include lt iostream h gt void main int x 5 if x 5 cout lt lt five lt lt endl else if x 6 cout lt lt Six lt lt endl e What will be the output of the following segment struct number int no1 no2 void display number n cout lt lt Number1 lt lt n no1 lt lt Number2 lt lt n no2 lt lt endl void main number n1 10 100 n2 n3 n3 n1 ni no1 5 n2 n3 n2 no1 5 n2 no2 2 n3 no1 1 display n1 display n2 display n3 f convert 4A8c 1 into binary number Q No 5 a Write a program to find the factorial of any given number
5. main WORKER W1 W2 W3 In this case we can create structure variable anywhere in the program If declared globally the structure variables could be declared both from inside main and any other place outside main function including any other user defined functions If declared locally the structure variables could be declared only within the scope in which the structure has been defined 2 No data member should be initialized with any value within the structure declaration i e the following type of structure declaration is incorrect and cause error struct WORKER char name 45 gender M lt Invalid Initialization within structure scope age 16 rate 100 00 4 2 2 Structure Variable Initialization Structure variables could be initialized by two ways e Static Initialization During design time e Dynamic Initialization Passing values during Runtime Static Initialization WORKER w1 structure variable declaration w1 name Ramu w1 gender M static initializations w1 age 17 w1 rate 100 00 The operator here is known as component operator used to access the data members composing the structure variable 129 There is also one another way for static initialization WORKER w1 Ramu M 17 100 00 Warning The declaration as well as initialization should be in the same line Dynamic Initialization main WORKER w1
6. cin gt gt num cout lt lt nThe factorial of the number lt lt factorial num getch c include lt iostream h gt include lt conio h gt include lt stdio h gt void main char str 300 int i charcount 0 words 1 lines 1 clrscr cout lt lt nEnter the Paragraph ie message n gets str for i 0 str i 0 i charcount if str iJ words if charcount 80 0 linest cout lt lt nNumber of Characters in the entered message lt lt charcount cout lt lt nNumber of Words in the entered message lt lt words cout lt lt nNumber of Lines in the entered message lt lt lines getch d include lt iostream h gt include lt conio h gt void main clrscr int A 20 N i j temp cout lt lt nEnter the number of elements cin gt gt N for i 0 i lt N i cin gt gt A i Bubble sort technique for i 0 i lt N i for j 0 j lt N 1 i j if A jJ gt Afj 1 Temp Ajj AGFA 1 A j 1 Temp cout lt lt The Elements in the array after sorting for i O i lt N i cout lt lt A i lt lt t e include lt iostream h gt include lt conio h gt include lt math h gt void main clrscr double d1 d2 b a c d cout lt lt nEnter the value of b a and c cin gt gt b gt gt a gt gt Cc d b b sqrt 4 a c if d 0 cout lt lt nRoots are equal or distinct else if d gt 0 cout lt lt nRoots are Re
7. cout lt lt Input Worker s Name cin getline w1 name 45 cout lt lt Input Worker s Gender cin gt gt w1 gender 4 2 3 Structure variable assignments We know that every variable in C can be assigned any other variable of same data type i e ifinta 7 b 3 we can write a b assigning the value of b to variable a Similar is the case with Structure variables also i e if WORKER w1 Ramu M 17 100 00 WORKER w2 we can write w2 w1 assigning the corresponding individual data member values of w1 to Worker w2 or WORKER w2 w1 Note Both structure variables must be of same type i e WORKER There is a member wise copying of member wise copying from one structure variable into other variable when we are using assignment operator between them So it is concluded that Writing w1 name w1 name w1 gender w2 gender w1 age w2 age w1 rate w2 rate is same as w1 w2 Though we can copy the contents of similar types of structure variables two dissimilar types of structure variables can t be assigned to each other even though they may have same types of constituent data members Assigning values into dissimilar structure variable would cause a incompatible data type error Consider the two different structures Student and Worker The Student structure can be written as struct Student char name 45 char gender int age float
8. void main inta 0 b 0 cout lt lt Input two numbers cin gt gt a gt gt b cout lt lt The sum of numbers are lt lt a b The above program is a very basic program which asks two integer values from user and prints out their sum In the above program you may observe that various programming elements like lt a b lt lt gt gt int void main Input two numbers are being used Work out yourself Identify each of the above programming elements and write its name using a table Students the program above is very simple to be thought written and executed but in real industrial programming situation we seldom get such programs to write There are many complex situation in life where we often need to write programs using few advanced programming elements Let us investigate few of the real life situations a Ram needs to find out whether any number is divisible by both 3 and 5 b A shopkeeper wants to give x discount on a particular purchase only when the net purchase by his customer exceeds Rs 1000 c A teacher wants to calculate the average marks for each of his 40 pupils in a class d Suresh wants to continue his program till he is pressing escape button on keyboard Can you program the above programming problems using the programming elements of C which you have learn till now Your answer would be probably a NO because the C programming elements which you have
9. 3 Write a program to find the total number of characters lines and words in a paragraph of text 4 A include lt iostream h gt include lt conio h gt include lt stdio h gt void main char str 300 int i charcount 0 words 1 lines 1 clrscr cout lt lt nEnter the Paragraph ie message n gets str for i 0 str i 0 i charcount if str iJ words if charcount 80 0 linest cout lt lt nNumber of Characters in the entered message lt lt charcount cout lt lt nNumber of Words in the entered message lt lt words cout lt lt nNumber of Lines in the entered message lt lt lines getch d Write a program to sort an array on N numbers in ascending order Avoid duplication of elements A include lt iostream h gt include lt conio h gt void main clrscr int A 20 N i j temp cout lt lt nEnter the number of elements cin gt gt N for i 0 i lt N i cin gt gt Ali Bubble sort technique for i 0 i lt N i for j 0 j lt N 1 i j if A jJ gt Alj 1 Temp Alj AUjJ AUi 1 A j 1 Temp cout lt lt The Elements in the array after sorting for i 0 i lt N i cout lt lt A i lt lt t e Write a program to find the roots of a quadratic equation A include lt iostream h gt include lt conio h gt include lt math h gt void main clrscr double d1 d2 b a c d cout lt lt nEnter the value
10. Also the CBSE has modified the marks distribution for Unit II and Unit IV same is incorporated herein I am glad to express my sincere gratitude to Ms R KALAVATHI Deputy Commissioner KVS RO Bhubaneswar and the other team members for preparing such an exhaustive study material At the end I would also extend my sincere thanks to Ms SARITA NASWA Asst Comm KVS RO Mumbai and our Principal Ms PRAMILA PAL for having extended timely guidance and support KAMAL KISHOR SWAMI PGT Comp Sc KV BHANDUP Mumbai SUPPORT MATERIAL COMPUTER SCIENCE 2013 14 CBSE Mark Distribution for different Units Unit Name UNIT 1 Computer Fundamental UNIT 2 Introduction to C UNIT 3 Programming Methodology UNIT 4 Programming in C Total Marks Weightage to different forms of questions Forms of Question Marks for each No of question Questions Very Short Answer Questions VSA 01 09 Short Answer Questions Type 1 SA1 02 13 Short Answer Questions Type II SAID 03 05 Long Answer Questions LA 04 05 Total 32 Difficulty Level of Questions Estimated Difficulty Level Percentage of questions Easy 15 Average 70 Difficult 15 INDEX Topics Unit 1 Computer Fundamentals Unit 2 Introduction to C Unit 3 Programming methodology Unit 4 Programming in C Sample Papers Detailed
11. Both these great inventions earned him the title of Father of Modern Computers In 1944 Prof Howard Aiken in collaboration with IBM constructed an electromechanical computer named Mark 1 which could multiply two 10 digit numbers in 5 seconds This machine was based on the concept of Babbage s Analytical engine and was the first operational general purpose computer which could execute preprogrammed instructions automatically without any human intervention In 1945 Dr John Von Neumann proposed the concept of a stored program computer As per this concept the program and data could be stored in the same memory unit According to Von Neumann architecture the processor executes instructions stored in the memory of the computer Since there is only one communication channel the processor at a time can either fetch data or an instruction That means at one point of time either the data or an instruction can be picked fetched from the storage unit for execution by the processor Hence execution takes place in sequential manner This limitation of Von Neumann Computer is known as Von Neumann bottleneck EDVAC Electronic Discrete Variable Automatic Computer was the first stored program computer developed in 1952 After the invention of first electronic computer ENIAC Electronic Numerical Integrator and Calculator in 1946 the computer technology improved tremendously and at very fast pace Generation of Computers Growth in the computer indus
12. Briefly Distinguish between a general purpose and special purpose computer Q No 2 a what is the shortcut menu what is its significance 2 b what is the significance of Recycle Bin 2 c Explain the concept of time sharing 2 d What is meant by the term multiprogramming and multitasking 2 e Explain briefly the function performed by an operating system as processor manager 2 Q No 3 a 4 Differentiate between object oriented programming and procedural oriented programming with the help of examples of each 3 A Procedure Oriented Programming A program in a procedural language is a list of instructions where each statement tells the computer to do something The focus is on the processing There is no much security for the data Object Oriented Programming The object oriented approach views a problem in terms of objects involved rather than procedure for doing it In object oriented programming object represents an entity that can store data and has its interface through functions b Distinguish between if and switch statement A The if else and switch both are selection statements and they both let you select an alternative out of given many alternatives by testing an expression But there are some differences in their operations i The switch statement differs from the if statement in that switch can only test for equality whereas if can evaluate a relational or logical expression le multiple conditions ii The switc
13. For example when viewing a student s record the user can follow a link to the student s class and from there a link to the student s teacher and from there a link to the teacher s other classes and so on amp Payroll System Payroll Management System software is used by all modern organizations to keep track of employees of the organization who receives wages or salary All different payment amounts are calculated by the payroll software and the record is maintained The software keeps track of personal records of employees viz name address date of birth qualification date of joining etc It also keeps track of professional record viz allowances perks income tax insurance etc Different reports pay slips etc can be generated through this software x Financial Accounting Financial accounting System is used to prepare accounting information maintain different accounts ledger and account books It also helps an organization to make budget x Hotel Management Hotel management software refers to management techniques used in the hotel sector These can include hotel administration accounts billing marketing housekeeping front office or front desk food and beverage management catering and maintenance Even advance bookings can be made through this software Customers can have a look at the hotel and the rooms before making bookings At any point of time the room availability tariff for each type of room and even booking status
14. If none of the n if conditions gets satisfied then the last else part always gets executed It is not compulsory to add an else at the last of the ladder Example char ch getch if ch gt a amp amp ch lt z cout lt lt you have inputted a lowercase alphabet else if ch gt A amp amp ch lt Z cout lt lt you have inputted an uppercase alphabet else if ch gt 0 amp amp ch lt 9 cout lt lt you have inputted a digit else cout lt lt you have inputted any special character or symbol In above code snippet a character is being inputted from user and is being checked upon by various if condition as alphabets digit or any other special symbol If the first condition gets satisfied then the character inputted is a lower case alphabet if not then the second if is evaluated if the second if gets satisfied then the character is an upper case alphabet if not then the third if is being evaluated if it is satisfied then the character is a digit if not then finally it is inferred as any other symbol in the last else The benefit of this type of conditioning statement is that we can have multiple conditions instead of just having one or two as seen in case of earlier if constructs Workout yourself A date in the format of dd mm yyyy when dd mm and yyyy are inputted separately is said to be a valid date if it is
15. Recordable Data can be recorded on these disks but only once So we can write data on these disks through a read write CD drive but after that the disk cannot be erased modified CD RW It stands for Compact Disk Rewritable It can be read or written multiple times But a CD RW drive needs to be installed on your computer DVD It stands for Digital Versatile Disk or Digital Video Disk It looks just like a CD and use a similar technology as that of the CDs discussed above but employ a shorter wave length red laser that permits a narrower beam This allows tracks to be spaced closely enoughfh to store data that is more than six times the CD s 700MB capacity It is a significant advancement in portable storage technology DVDs consist of two half thickness 0 6 mm CD like discs glued back to back This protects the delicate reflective coating as it is on the inside of the disc Also it makes possible to have double sided DVDs where data can be stored on each half disc A DVD holds 4 7 GB to 17 GB of data That means a complete movie can be stored on one side of a DVD Like CDs DVDs also come in three varieties x DVD ROM amp DVD R amp DVD RW Blue Ray Disk This is the latest optical storage media to store high definition audio and video It looks like a CD or DVD but can store up to 27 GB of data on a single layer disk and up to 54 GB of data on a dual layer disk Where CDs or DVDs use red laser beam the blue ray disk uses a b
16. System Clock is an electronic circuit that generates pulses which are measured in million of cycles per second MHz The number of pulses generated by the clock per unit of time is its Clock speed Each microprocessor is characterized by its clock speed Nowadays microprocessors have clock speed of several GHz The CPU uses this clock speed to control sequencing and execution of various operations in the computer Classification of Microprocessors Apart from the width of data word length that the microprocessors can process at a time the classification is also based on the architecture i e Instruction Set of the microprocessor While studying about CPUs we come across two abbreviations CISC and RISC amp RISC It stands for Reduced Instruction Set Computer It is a type of microprocessor architecture that uses a small set of instructions of uniform length These are simple but primitive instructions which execute in one clock cycle For this reason RISC chips are less complex and also less expensive 34 to produce The instructions are of uniform length which interface with about 32 36 registers The program size in case of RISC architecture is more but more memory cycles are needed to access data To reduce the number of memory cycles RISC keeps the necessary data in the processor itself The drawback of RISC design is that the computer must combine or repeat operations to complete a large program consisting of many processing operation
17. The output of the code will be 10 instead of 3 So whenever you don t want to restrict your parameter to a fixed value declare it as const Some compiler may produce error cout lt lt x myFunction 3 even if the function is passed with a value 3 it will not accept check your progress Write a function waf to find the largest out of three integers as input parameters W a f to find whether a number either divisible by its predecessor and successor W a f which returns the sum of digits of any integer passed to it as parameter W a f to calculate discount amount on a given rate of item and discount offered 3 1 2 Library Functions These functions are ready made functions available with C compiler They are stored under various header files A header file is a normal C program file with h extension containing the code for all the C functions defined under it Header files group functions according to its use and common feature 111 Following are some important Header files and useful functions within them 1 stdio h standard I O function gets puts 2 ctype h character type function i isalnum isalpha isdigit islower isupper tolower toupper string h string related function strcpy strcat strlen strcmp strempi strrev strupr strlwr math h mathematical function f fabs pow sqrt sin cos abs 5 st
18. and each register inside the CPU has a specific function like storing data storing an instruction storing address of a location in memory etc The user registers can be used by an assembly language programmer for storing operands intermediate results etc Accumulator ACC is the main register in the ALU and contains one of the operands of an operation to be performed in the ALU Memory It facilitates the remembrance power to computer system It refers to the physical devices used to store programs sequences of instructions or data e g program state information on a temporary or permanent basis for use in a computer or other digital electronic device The term primary memory is used for the information in physical systems which are fast i e RAM as a distinction from secondary memory which are physical devices for program and data storage which are slow to access but offer higher memory capacity Primary memory stored on secondary memory is called virtual memory Primary Memory can be categorized as Volatile Memory amp Non Volatile Memory Volatile memory RAM Volatile memory is computer memory that requires power to maintain the stored information Most modern semiconductor volatile memory is either Static RAM or dynamic RAM SRAM retains its contents as long as the power is connected and is easy to interface to but uses six transistors per bit Dynamic RAM is more complicated to interface to and control and needs regular refre
19. arr i cout lt lt The minimum of all is lt lt min lt lt and the maximum is lt lt max Check your progress 1 Write a program to store 10 elements and increase its value by 5 and show the array 2 Write the program to divide each of the array element by 3 and show the array 3 Write a program to find the average of all elements of an array of size 20 4 Write a program to find second minimum value out of an array containing 10 elements 4 2 Strings Array of characters Strings are in fact sequences of characters we can represent them also as plain arrays of char elements terminated by a 0 character For example the following array char myStr 20 is an array that can store up to 20 elements of type char It can be represented as myStr H e T j o o 0 ee 2 ae OS see te ute 19 Therefore in this array in theory we can store sequences of characters up to 20 characters long But we can also store shorter sequences For example myStr could store at some point in a program either the sequence Hello or the sequence Merry christmas since both are shorter than 20 characters Therefore since the array of characters can store shorter sequences than its total length a special character is used to signal the end of the valid sequence the null character whose literal constant can be written as 0 backsla
20. computers and some other electronic devices for data communication It is a single low cost plug n play connector The operating system automatically detects the device connected through the USB port USB ports have become very popular these days as they connect many different devices to the computer these days Most computers have USB ports on front back and or sides of system unit Flash drives digital cameras printers scanners are some of the devices that often connect through the USB port Infrared Port In this type of port data is transmitted through Infrared waves For infrared transmission the device and the computer both must have infrared ports These allow computers and peripherals to communicate serially over an Infrared link rather than over cables The remote control of our TV sets uses the same technology For wireless data communication between computers and various peripheral devices we use infrared ports Bluetooth Port Bluetooth is used to connect mobile phones computers and PDAs using a short range wireless connection This technology uses radio waves to transmit data between any two devices The devices that are Bluetooth enabled contain a small transceiver chip that allows them to communicate with other 40 Bluetooth enabled computer or device Data can be exchanged at the rate of about 2 megabit per second Fire wire Port FireWire ports are forms of a serial port that make use of FireWire technology to
21. peripherals to the computer with a cable that attaches to one of the ports A port s main function is to 39 act as a point of attachment where the cable from the peripheral device plugs into the system unit allowing data to flow from the peripheral device Some of the common sockets ports are power socket for connecting power cable PS2 ports for connecting Mouse amp Keyboard USB Port for connecting USB devices such as mouse keyboard printer pen drive etc and VGA port for connecting Monitor Screen Some ports are discussed in detail below Serial Port Through a serial port data is transmitted travels one bit at a time through a single wire The data transmission speed is quite slow Serial ports are commonly known as communication COM ane or RS232C ports and connect devices like mouse and modem These ports are rarely used these days Parallel port These ports were earlier used to connect printers to the computer system A parallel port can send 8 bits 1 byte at a time simultaneously in parallel Hence data transmission is faster through these ports Parallel ports are used to connect printers scanners CD writers etc PS 2 Port This is a round port for plugging in keyboard or mouse It has a P rag with a mini DIN connector These ports are becoming obsolete now some systems these days do not have PS 2 ports USB Port A USB Universal Serial Bus port is a standard cable connection interface available on personal
22. pure The above loop will not execute at all because the loop condition is failing at first time 2 2 2 do while loop construct A do while loop is identical to a while loop in every sense except that it is guaranteed to perform the instructions inside once before testing for the ending condition Syntax Example Consider the following code snippet to find factorial of a given number n int f 1 int n 0 cin gt gt n do f f n Sr A i while n gt 0 cout lt lt The factorial of lt lt n lt lt is lt lt f Lets us analyze the execution of the above program the factorial of any number n is evaluated as fact n n 1 n 2 1 This means that with each iteration the value of n is decremented by 1 and is multiplied with the previous value of n is stored cumulatively The iteration cycle stops when n is decremented upto a value equal to 1 Let us conduct a Dry run on the above code snippet to understand the flow of logic for n 4 Initially f 1 n 4 1 Iteration cycle f 1 4 4 n 3 condition n gt 0 evaluates as true hence loop is continued 2 Iteration cycle f 4 3 12 n 2 condition n gt 0 evaluates as true hence loop is continued 3 Iteration cycle f 12 2 24 n 1 condition n gt 0 evaluates as true hence loop is continued 4 teration cycle 93 f 24 1 24 n 0 condition n gt 0 evaluates as false as 0 0 hence loop is terminated and program flow comes
23. switch var1 case lt value1 gt break case lt value2 gt break case lt value 3 gt break Ask your teacher which of the constructs can be nested within which of the other constructs Check Your Progress 1 Find the output of the code given below include lt iostream h gt void main int x 3 switch x case 1 cout lt lt One break case 2 cout lt lt Two break case 3 cout lt lt Three case 4 cout lt lt Four case 5 cout lt lt Five break Find error in following code include lt isotream h gt void main int a 10 int b 10 int c 20 switch a case b cout lt lt Hurray B break Case C cout lt lt Hurray C break default cout lt lt Wrong code break 2 2 Iterative Constructs Looping Iterative constructs or Loops enables a program with a cyclic flow of logic Each statement which is written under the scope of a looping statement gets executed the number of times the iteration looping 89 continues for In previous chapter we have seen few real life scenarios where a looping construct is needed for performing a particular set of tasks repeatedly for a number of times Now we will go into details of all looping constructs available in C In C there are three basic types of looping constructs available they are while loop keyword while is used to loop do while loop
24. void main float prnc 5000 rt 10 tm 5 float si 0 0 first call produces si Rs 2500 si getSimplelnt prnc rt tm second call produces si Rs 500 si getSimplelnt prnc rt last parameter is omitted as it was declared as as optional type with a default value 1 3 2 3 Arguments passed by value and by reference Until now in all the functions we have seen the arguments passed to the functions have been passed by value This means that when calling a function with parameters what we have passed to the function were copies of their values but never the variables themselves For example suppose that we called our first function addition using the following code int x 5 y 3 Z z addition x y What we did in this case was to call to function addition passing the values of x and y i e 5 and 3 respectively but not the variables x and y themselves int addition int a int b to f z addition 5 3 4 This way when the function addition is called the value of its local variables a and b become 5 and 3 respectively but any modification to either a or b within the function addition will not have any effect in the values of x and y outside it because variables x and y were not themselves passed to the function but only copies of their values at the moment the function was called But there might be some cases where you need to manipulate from inside a function the value of an
25. 20 m 6 m 7 m 20 c True and false d String h and stdio h e The conditional operator is a ternary operator it takes three operands The conditional operator works as follows e The first operand is implicitly converted to bool It is evaluated and all side effects are completed before continuing e f the first operand evaluates to true 1 the second operand is evaluated e f the first operand evaluates to false 0 the third operand is evaluated The result of the conditional operator is the result of whichever operand is evaluated the second or the third Only one of the last two operands is evaluated in a conditional expression Ex expre_Expressions_with_the_Conditional_Operator cpp 145 compile with EHsc II Demonstrate conditional operator include lt iostream gt using namespace std int main inti 1 j 2 cout lt lt i gt j i j lt lt is greater lt lt endl f Operator is used to find the quotient while is used to find the remainder in the c expression for ex int a 5 b 2 c if c a b the result of c will be 2 and if c a b the value of c will be 1 Q No 4 a A function prototype is a declaration of the function that tells the program about the type of the value returned by the function and the number and the type of arguments The prototype declaration looks just like a function definition except that it has no body Ex void abc b break makes the compiler to tr
26. Academics Accounts Sub modules Sub modules Sub modules Admission Student Registration Pay amp Allowances Construction Examination Audit Purchase Recruitment Results When the whole software is divided into modules as seen in the above case scenario then the following benefits could be harvested i Each module can be tracked individually and separately without taking much care of other modules ii A module is a reusable piece of program which could used again and again Suppose that Navodaya Vidyalaya now wants to make a software like KVS then they can re use the same modules of KVS with some changes customization iii If error is found in one module the functionality of that particular module and its associated modules would be disturbed the whole software will not suffer Thus errors can be tracked easily and debugged in much less time because programmer will know which module is causing error so he will debug that particular module only not the whole software much when you visit doctor suffering from common cold the doctor does not checks your brain iv System up gradation the process of changing from older system to newer one becomes much easier because only those modules which needs up gradation will be dealt leaving other things as it is So we see that modularization of a system gives us much independence and flexibility in terms of fast program development easier debugging and
27. Evaluate the following where p q are integers and r f are floating point numbers The value of p 8 q 4 and r 2 5 i f p q p q ii r ptq p q 4 a What is the output of the following i include lt iostream h gt void main int i 0 Cout lt lt i lt lt lt lt j lt lt lt lt j lt lt endl CouUt lt lt j lt lt lt lt j lt lt lt lt j lt lt endl ii include lt iostream h gt void main a 3 a at1 if a gt 5 cout lt lt a else cout lt lt a 5 iii What will be the output of the following program segment If input is as a g b b c e d p cin gt gt ch switch ch case g cout lt lt Good case b cout lt lt Bad break case e cout lt lt excellent break default cout lt lt wrong choice iv Determine the output for i 20 i lt 100 i 10 j i 2 cout lt lt j lt lt v What output will be the following code fragment produce void main int val res n 1000 cin gt gt val res n val gt 1750 400 200 cout lt lt res i if val 2000 ii if val 1000 iii if val 500 5 a Find the error from the following code segment and rewrite the corrected code underlining the correction made 2 include iostream h void main int X Y cin gt gt gt X for Y 0 Y lt 10 Y if X cout lt lt Y X else cout gt gt Y b Convert the following code segment into
28. Later magnetic disks also came into existence and were used as secondary storage devices All these new developments transistors magnetic core memory and magnetic disk storage devices made the computers more powerful and reliable This further led to the existence of operating systems Programming languages like FORTRAN COBOL Algol etc also developed Commercial applications of the computer increased and now the computers were used in business and industries for applications like payroll employee management inventory control etc IBM 1401 and IBM 1620 were popular computers of this generation Examples IBM 1401 IBM 1620 UNIVAC 1108 The Third Generation 1964 1975 In 1964 the Integrated Circuits or ICs or chips revolutionized the electronic industry and started the third generation of computers An IC is a small silicon chip or wafer made up of extremely purified silicon crystals It has numerous transistors capacitors resistors and other elements of an electronic circuit A small scale integration SSI chip used to have about 10 transistors on a single chip and a medium scale integration MSI chip had about 100 transistors per chip The size of memories also increased Various mainframe computers and minicomputers were developed during this generation Even operating systems with multitasking and multiprogramming features you will learn about these terms in the next chapter were developed Since ICs made the computers highly reliable
29. O Text I 0 1 if isalpha Text I Text l else if isupper Text I Text l Text l 1 else Text I Text I 1 cout lt lt Text i What are differences between for and do while loop explain with example j How can you define Global Variable and Local Variable Also give a_ suitable C code to illustrate both a Write a program to print the left and right diagonal element of an NXN matrix b b Write a program to find the factorial of a number recursive function c Write a program to find the total number of characters lines and words in a paragraph of text d Write a program to sort an array on N numbers in ascending order Avoid duplication of elements e Write a program to find the roots of a quadratic equation Answer Key Q No 1 a My Computer is used to viewing the contents of a single folder or drive Also the things we have on our computer Your Programs Documents and data files for example are all accessible from form one place called My Computer b Types of operating system i Single User ii Multiuser iii Time Sharing iv Real Time v Multiprocessing vi Interactive c An operating system is a program which acts as an interface between a user and the Hardware Functions i Process Management and Storage Memory Management Note Students has to explain both in brief d An interpreter converts source program HLL into object program LLL line by line whereas compiler con
30. Purpose and Customized Study the need functions and types of operating system Study some commonly used operating systems UNIX LINUX Windows Solaris BOSS Study mobile operating systems Android and Symbian Understand Open Source Concepts Open Source Software Freeware Shareware Proprietary Software Software can be broadly are categorized as System Software x Application Software x Utility Software System Software System Software is the software that is directly related to coordinating computer operations and performs tasks associated with controlling and utilizing computer hardware These programs assist in running application programs and are designed to control the operation of a computer system System software directs the computer what to do when to do and how to do System software can be further categorized into Operating System Language Translators Operating System An Operating system is the most important system software It is a set of programs that control and supervise the hardware of a computer and also provide services to application software programmers and users It manages all hardware and software input output and processing activities within the computer system the flow of information to and from the processor sets priorities for handling different tasks and so on Without operating system a computer cannot do anything useful When a computer is switched on the operating system is the first p
31. Statements In this program some portion of the program is executed based upon the conditional test If the conditional test is true compiler will execute some part of the program otherwise it will execute the other part of the program Example Write an algorithm to check whether he is eligible to vote more than or equal to 18 years old Step 1 Start Step 2 Take age and store it in age Step 3 Check age value if age gt 18 then go to step 4 else step 5 Step 4 Print Eligible to vote and go to step 6 Step 5 Print Not eligible to vote Step 6 Stop Example Write an algorithm to check whether given number is ve ve or zero Step 1 Start Step 2 Take any number and store it in n Step 3 Check n value ifn gt 0 then go to step 5 else go to step 4 Step 4 Check n value ifn lt 0 then go to step 6 else go to step 7 Step 5 Print Given number is ve and go to step 8 Step 6 Print Given number is ve and go to step 8 Step 7 Print Given number is zero Step 8 Stop In the above mentioned examples all the statements are not executed but based upon the input some portions of the algorithm are executed because we have true or false situation in the program Iterative statements In some programs certain set of statements are executed again and again based upon conditional test i e executed more than one time This type of execution is called looping or iteration Exampl
32. a string include lt iostream h gt include lt stdio h gt int main char string 35 int count 0 cout lt lt Input a string gets string library function in stdio h to input a string for int i 0 string i 0 i if string i a string i e string i o string i u string i i string i A string i E string i O string i U string i l count In the above program the loop is iterated till the character at ith location matches with null character because after that there is no character left to be scanned So scanning of characters from first to last character is done using for loop and if vowels are found count keeps incrementing String related library functions There are few string related library functions in header file string h which are very useful when we work with strings They are i strlen char it accepts a string as parameter and returns the length of the string i e number of characters within the string For example strlen Hurray will return 6 ii strepy char char it accepts two strings as input parameters and then copies the second into the first For example char mstr Suresh char ystr 20 strcpy ystr mstr copies content of mstr into ystr puts mstr prints Suresh iii strrev char it accepts a string reverses its content and stor
33. a suitable data type For example in the given problem the following data types must be used to store information related to a Worker Data Data Type C Declaration Total Size in bytes Name char char name 45 45 x 1 45 bytes Sex char char sex M 1x1 1 byte Age int int age 15 1x2 2 bytes Rate per Day float float rate 100 00 1x4 4 bytes So to store the information of 20 Workers one has to declare a total of 4 x 20 80 variables The variable declarations in the program would be like char name1 45 name2 45 name3 45 name20 45 char gender1 gender2 gender3 gender4 int age1 age2 age 3 age20 float rate1 rate2 rate3 rate20 Conclusion Using the above methodology we find that as the number of worker increases the number of variables also increases and thus it becomes difficult task to manage these huge number of variables 126 Using Arrays The drawbacks of the previous method of information storage could be managed up to some extent if instead of taking separate variables for storing related information of Workers say Age we could have used an array of Age which would store the age of all 20 employees Though this method does not provides a economic solution in terms of memory it provides a better management of Memory locations where the information about the employees would be stored So fo
34. ahead when we begin to use pointers At this point it is important to be able to clearly distinguish between the two uses that brackets have related to arrays They perform two different tasks one is to specify the size of arrays when they are declared and the second one is to specify indices for concrete array elements Do not confuse these two possible uses of brackets with arrays int myArr 5 declaration of a new array myArr 2 75 access to an element of the array If you read carefully you will see that a type specifier always precedes a variable or array declaration while it never precedes an access 118 Some other valid operations with arrays myArr O a myArr a 75 b myArr a 2 myArr myArr a myArr 2 5 program 4 1 adding all the elements of an array include lt iostream gt using namespace std int myArr 16 2 77 40 12071 int n result 0 int main for n 0 n lt 5 n result myArr n cout lt lt result return 0 Output 12206 Dynamic Initialization Arrays can also be initialized during runtime The following program shows how to input values into arrays during rum time program 4 2 Inputting value in an array during run time include lt iostream h gt main int my_arr 5 name of array cout lt lt nEnter values at for int i 0 i lt 5 i cout lt lt n lt lt j 1 lt lt
35. an indispensable part of our lives The manner in which computers have revolutionised our lives because of their accuracy and speed of performing a job is truly remarkable Today no organization can function without a computer In fact various organizations are trying to become paper free owing to benefits of computers But the computers of today have evolved over the years from a simple calculating device to the portable high speed computers that we see today Evolution of Computers The growth of computer industry started with the need for performing fast calculations The manual method of computing was slow and prone to errors So attempts were made to develop faster calculating devices The journey that started from the first calculating device i e Abacus has led us today to extremely high speed calculating devices Let us first have a look at some early calculating devices and then we will explore various generations of computer Abacus Abacus was discovered by the Mesopotamians in around 3000 BC An abacus consisted of beads on movable rods divided into two parts Fig 1 Addition and multiplication of numbers was done by using the place value of digits of the numbers and position of beads in an abacus The Chinese further improved on the abacus so that calculations could be done more easily Even today abacus is considered as an apt tool for young children to do calculations In an abacus each row is thought of as a ten s place From ri
36. and is built inside the CPU It is fast as compared to L2 cache Hoani x L2 cache It is large but slower and is mounted i on the motherboard al eee EN g Secondary Memory The major limitation of primary memory is that it has limited storage capacity and is volatile To overcome this limitation we have secondary memory storage devices This type of memory is also called external memory It refers to the various storage media on which a computer can store data and programs It is an additional storage not part of the main computer The Secondary storage media can be fixed or removable Fixed Storage media is an internal storage medium like hard disk that is fixed inside the computer Removable storage media is a data storage medium that is portable and can be taken outside the computer Why do we need Secondary Memory Secondary memory is needed because of the following reasons a For permanence As the RAM is volatile i e it loses all information when the electricity is turned off something is needed for permanence Secondary storage devices serve this purpose They do not lose data when electricity is turned off b For portability Secondary storage like the CDs flash drives can be used to transport data from one computer to another Secondary Storage Media There are the following main types of storage media a Magnetic b Optical c Solid State Magnetic storage media Examples of magnetic storage media are hard
37. designed using word processing software Features like Mail Merge Macro has further enhanced the word processing software and made it very useful x Presentation Tools Presentation tools is a general purpose application software that lets us create presentations on any topic We can not only create a presentation and add slides into that but also can use different types of background fonts animations audio video etc We can add clipart and other graphics into our document Even audio video files can be added on to the presentations Popular examples of Presentation tools software are Impress open office and Microsoft Power Point x Spreadsheet Packages Spreadsheet is a general purpose application software that lets us create and store data in tabular form Both text and numerical values can be entered in that tables known as a spreadsheet We can not only create a document and add data into that but also can create different types of charts and graphs based upon the numerical data stored in that page All common mathematical and statistical formulae can be used on the numeric data Popular examples of Spreadsheet software are Calc Open Office and Microsoft Excel x Database Management System Database Management System is general purpose application software that lets us create computer programs that control the creation maintenance and the use of database for an organization and its end users We can not only store data but can also manage d
38. difficult for us to write computer program directly in machine code The programs are written mostly in high level languages i e BASIC C Python etc A program written in any high level programming language or written in assembly language is called the Source Program or Source Code The source code cannot be executed directly by the computer The source code must be converted into machine language to be executed The program translated into machine code is known as Object Program or Object code The special translator system software that is used to translate the program written in high level language or Assembly language into machine code is called language processor or translator program The language processors can be any of the following three types Assembler Compiler and Interpreter Assembler The Assembler is used to translate the program written in Assembly language into machine code The input of Assembler is a source program that contains assembly language instructions The output generated by assembler is the object code or machine code understandable by the computer Compiler The language processor that translates the complete source program as a whole in onego into machine code is called compiler Some of the examples are C and C compilers The program translated into machine code is called the object program The source code is translated to object code successfully if it is free of errors If there are any errors in the source c
39. disks floppy disks and magnetic tapes Magnetic media is coated with a magnetic sensitive layer and this layer is magnetized in clockwise or anticlockwise directions which then are interpreted as binary Is and Os at reading Floppy Disk Diskette A floppy disk is a flexible disk made up of mylar with a magnetic coating on it It is packaged inside a protective plastic envelope These were one of the oldest type of portable storage devices that could store up to 1 44 MB of data but now they are no longer in use Hard disk A hard disk consists of one or more circular disks called platters which are mounted on a common spindle Each surface of a platter is coated with a magnetic material Both surfaces of each disk are capable of storing data except the top and bottom disk where only the inner surface is used The information is recorded on the surface of the rotating disk by magnetic read write heads These heads are joined to a common arm knjown as access arm This arm moves over the surface of the rotating Information is recorded on each of these disks in the form of concentric circles called tracks which are further divided into sectors Hard drives however are not very portable and are primarily used internally in a computer system But external hard disks are also available as a substitute for portable storage Today the hard disks have the storage capacity of several gigabytes to terabytes Optical storage media On an optical s
40. environment Hence time sharing operating system is very useful in network environment as each user is allowed to share the network resources x Device Management The Operating System communicates with hardware and the attached devices and maintains a balance between them and the CPU This is all the more important because the CPU processing speed is much higher than that of I O devices In order to optimize the CPU time the operating system employs two techniques Buffering and Spooling Buffering In this technique the temporary storage of input and output data is done in Input Buffer and Output Buffer Once the signal for input or output is sent to or from the CPU respectively the operating system through the device controller moves the data from the input device to the input buffer and for the output device to the output buffer When the signal is sent to from the operating system to the respective device controllers the program doesn t wait rather it returns to its processing In case of input if the buffer is full the operating system sends a signal to the program which processes the data stored in the buffer When the buffer becomes empty the program informs the operating system which reloads the buffer and the input operation continues Similarly for output when the program being executed has to display some output it fills the buffer and then informs the operating system Thereafter the operating system empties the buffer by sending d
41. first will test the condition and if condition is true then only the body of the loop will be executed While do while loop is exit control loop and even the condition is not true at least one time the body of the loop will be executed b data types are means to identify the types of data and associated operation of handling it The fundamental data types are char int float double and void c one byte d i sqrt a atb b amp ii a b p q p q e students do yourself Q No 4 a i 012 456 ii 9 ili For g good amp bad for b bad for e excellent for p wrong choice iv 10 15 20 25 30 35 40 45 50 v 400 400 200 Q No 5 a Errors if x y correct if x y amp cout gt gt y correct cout lt lt y b int ch cin gt gt ch switch ch Case 1 cout lt lt Laptop break Case 2 cout lt lt Desktop break Case 3 cout lt lt Notebook break Default cout lt lt Invalid Choice Hinclude lt iostream h gt void main inti i 1 do cout lt lt n lt lt i while i lt 20 d In both condition output will be 6 5 Q No 6 a math h math h stdlib h ctype h b 1100 232 4226 1100100 Q No 7 a include lt iostream h gt include lt conio h gt void main clrscr int year cout lt lt Enter Year ex 1900 cin gt gt year if year 100 0 if year 400 0 cout lt lt nLeap Year else if year 4 0 co
42. from its scope Function 3 3 program to find the HCF of two inputted numbers void getHCF 105 void getHCF intn1 0 n2 0 int hcf 0 cout lt lt Input two numbers whose hcf is to be found cin gt gt n1 gt gt n2 if n1 n2 cout lt lt n1 else if n1 lt n2 for intd 1 d lt n2 d if n1 d 0 amp amp n2 d 0 hcf d cout lt lt The hef is lt lt het else for intd 1 d lt n1 d if n1 d 0 amp amp n2 d 0 hef d cout lt lt The hcf is lt lt het end of function Explanation Look at the function definition of the above function since the function is taking the two required inputs within its scope using cout and cin we had not passed any parameters to function thus we have kept the paranthesis empty Also as the function directly prints the output there is no need to return any value from its scope hence return type is void The logic of the function is simple we are finding the highest of the two numbers and then running a loop from 1 to the highest number and in each iteration we are finding out whether the iterator value divides both the numbers if it then we put that iterator s value into variable hcf changing the old value of variable hcf Thus at the end of the loop the hcf is left out with the Highest Common Factor and we print it with a cout Function 3 4 function to
43. height Compared to Worker Structure we find that the data types and sequence of all the data members of structure student is same as that of structure Worker but still we can never write Worker w Ramu M 20 5 5 So the following assignments are invalid assignments Students w Invalid assignment as s and w both are two different structures Students S W Invalid 4 2 4 Array of Structure Just like we can make array of integers floats chars we can also make array of user defined data types like structures The syntax to make such an array is lt structure_name gt lt array_name gt size where structure_name is the name of the structure which you have created array_name is any valid identifier size is a positive integer constant Example to create array of 20 Workers we can have Worker W 20 The above structure could be visualized as 0 W 0 W 1 w 2 wg W 3 sa tre W 19 Each of the elements of the array is itself a structure hence each of them have all the four components Initialization of Structure Array Array of structures like any other array can be initialized statically and dynamically runtime Static initialization The above array of Workers WI can be statically initialized as 131 Ramu M 17 100 00 Hari M 22 120 00 kajri F 18 100 00 values of other 16
44. inner block is continues as gt if 2000 400 0 gt jf 0 0 gt if true Since the second nested if condition evaluates out to be true it opens up its block and the next statement in the inner block is continues to print output on console as Year 2000 is a leap year Workout yourself i Google out to find that whether year 1900 was a leap year or not and then verify it using a dry run with the help of above program ii Try to implement the above code without using nested if construct Check your progress 1 Find error in code below and explain include lt iostream h gt void main Find the output of the code below void main int NoOfGirls 4 int NoOfBoys 10 if NoOfBoys 8 amp amp NoOfGirls lt NoOfBoys cout lt lt Great achievement else cout lt lt Greater achievement Find the output of the code below void main int circle 5 rectangle 0 square 4 triangle 0 if circle if rectangle square cout lt lt Draw diagram else if rectangle amp amp square cout lt lt Invalid diagram if circle rectangle square triangle cout lt lt Canvas Available cout lt lt Invisible diagram Find the output of code below void main intx 3 y 5 if x lt 5 cout lt lt Hurray else cout lt lt Trapped W
45. its table cin gt gt n cout lt lt Enter the number table upto cin gt gt m i 1 while i lt m r n i cout lt lt N lt lt lt lt lt lt lt lt R lt lt endl Sample Paper II Subject Computer Science Max Marks 70 Duration 3 hrs Note All questions are compulsory Q1 a What is significance of My Computer b Explain different types of operating systems c What is an Operating System Explain its any two functions d How is a compiler different from interpreter e Convert i 10 10 10 2 ii 101011 1110 2 Jo Q2 a What do you mean by run time error b what is the deference between if and if else statement c Mention and explain briefly any three characteristics of a good program d How can you give a single line and multiline comments in C explain with suitable examples 2 e what do you mean by header files What is the difference between include lt iostream h gt and include iostream h 2 Q3 a Classify the following variable names of c into valid and invalid category i 1no ii num 1 iii num iv num1num v num 1 vi num 1 b Give output of following code include lt iostream h gt int m 5 void check void main int m 20 int m 10 m cout lt lt m lt lt m lt lt m lt lt m lt lt endl check cout lt lt m lt lt m lt lt m lt lt m lt lt endl check cout lt lt m lt lt
46. keywords do and while are used to loop for loop keyword for is used to loop It is very important to understand that a looping construct enables repetition of tasks under its scope based on a particular condition called as loop condition This loop condition evaluates as true or false A loop may be continued till a loop condition is evaluated as true or false based on a particular program situation All the above mentioned three loops have three parts common in them i e the looping variable iterator the loop condition logic to change the value of iterator with each cycle iteration Let me show you distinguishably these three parts and then we will proceed to the syntax Iterator loop condition logic to modify iterator value for Eia some code Similarly while and do while also have these three significant parts as shown below int i 0 do isome code iste while i lt 7 2 2 1 while loop construct A while loop tests for its ending condition before performing its contents even the first time So if the ending condition is met when the while loop begins the lines of instructions it contains will never be carried out Awhile continues iteration cycle till its loop condition is evaluated as false If the loop condition is false for the first time iteration then loop will not execute even once Example intx 0 sum 0 cout lt lt Input a natural number cin gt gt x
47. loop he she may input after 3 cycles or 5 or may be 200 Workout yourself In the above program 2 3 remove the two shaded input line placed before the start of while construct and then execute the code to find whether you are getting same result as before or anything wrong If incorrect result is produced then find the reason explain it to class friends 2 2 3 for loop A for loop has all of its three parts i e the iterator variable loop condition and logic to continue loop kept intact at one place separated by semi colon This loop is also an Entry Control Loop as condition is checked before entering into the scope of the loop Let us analyze the syntax of a for looping Syntax for lt variable s initialization gt lt looping condition gt lt incrementing decrementing gt do something The first part of a for loop is a place where all looping variables are declared and initialized in the same way we declare multiple variables of a single data type e g inti O j 2 k 9 95 This part of the loop is executed only once at the start up of the loop and never it is executed again how can you re declare variables with the same name in same scope As per turbo c compiler the scope of all these variables declared in for loop is same as program scope i e they can be accessed from any other scope in the main but the current ISO C has changed this making the scope of all these varia
48. lt ch fabs pow sqrt sin cos abs Program 3 4 include lt iostream h gt include lt math h gt define PI 3 14159265 macro definition PI will always hold 3 14159265 int main cout lt lt The absolute value of 3 1416 is lt lt fabs 3 1416 abs also acts similarly but only on int data cout lt lt The absolute value of 10 6 is lt lt fabs 10 6 cout lt lt 7 0 3 lt lt pow 7 0 3 cout lt lt 4 73 12 lt lt pow 4 73 12 cout lt lt 32 01 1 54 lt lt pow 32 01 1 54 double param result param 1024 0 result sqrt param cout lt lt sqrt lt lt result result sin param PI 180 in similar way cos tan will be called cout lt lt The sine of lt lt param lt lt degrees is lt lt result return 0 randomize random itoa atoi The above functions belongs to header file stdlib h Let us observe the use of these functions randomize This function provides the seed value and an algorithm to help random function in generating random numbers The seed value may be taken from current system s time random lt int gt This function accepts an integer parameter say x and then generates a random value between 0 to x 1 for example random 7 will generate numbers between 0 to 6 To generate random numbers between a lower and upper limit we can use following for
49. m lt lt m lt lt m lt lt endl void check m c What will be result of following statements if a 5 b 65 initially i a lt 5 ii b lt 5 d Name the header file s that shall be needed for successful compilation of the following C code void main char name 40 strcpy name India puts name e Explain conditional operator with example in c f What is difference between and operators in c explain with a example 2 Q4 a What do you mean by function prototype in C 2 b Explain Break and Continue statement in C with example 2 c Find syntax error s if any in following program Assume all header files are present 2 main lt gt int c switch c case 1 5 cout lt lt India is great n break case 2 cout lt lt hello n break end of main end of switch d How will you declare and define i Array named mark with 10 integer values ii array named avg with 8 float values e Convert following while loop to for loop int x 0 while x lt 100 cout lt lt the value of x is n lt lt x cout lt lt done n X 2 f Define token g What is the difference between call by value and call by reference explain with suitable example h Find the output of the following program include lt iostream h gt include lt ctype h gt void main char Text Comp uter for int
50. memory chip contains thousands of memory locations In the computer the data is stored in the form of bits and bytes A bit is the smallest storage unit of memory A nibble is a collection of 4 bits Eight bits combined together to form a single byte which in turn represents a single character Other units of memory are KB Kilobyte MB Megabyte GB Gigabyte TB Terabytes PB Petabyte EB Exabytes ZB Zettabytes and YB Yottabytes Every higher unit is equal to 2 of the previous unit The smallest unit is bit which mean either 0 or 1 1 bit O0or1 1 Byte 8 bit 1 Nibble 4 bit 1 Kilo Byte 1024 Byte 2 Byte 1 Mega Byte 1024 KB 2 KB 1 Gega Byte 1024 MB 2 MB 1TeraByte 1024 GB 2 GB 1PetaByte 1024 TB 2 TB 1 Exa Byte 1024 PB 2 PB 1 Zetta Byte 1024 EB 2 EB 1 Yotta Byte 1024 ZB 2 ZB The computer memories can be divided into following categories x Primary Memory Secondary memory Cache Memory Primary Memory Primary memory or main memory is a Metal Oxide Semiconductor MOS memory used for storing program and data during the execution of the program It is directly accessible to CPU Memories can be both read from and written to are called read write memories On the other hand memories that have data or program permanently stored onto them and hence can be only read from are called Read Only memories Broadly primary memory can be of two types RAM Random Access Memory and ROM R
51. myArr would be 5 ints long since we have provided 5 initialization values Accessing the values of an array In any point of a program in which an array is visible we can access the value of any of its elements individually as if it was a normal variable thus being able to both read and modify its value The format is as simple as Syntax array_name Following the previous examples in which myArr had 5 elements and each of those elements was of type int the name which we can use to refer to each element is the following For example to store the value 75 in the third element of myArr we could write the following statement myArr 2 75 and for example to pass the value of the third element of myArr to a variable called a we could write a myArr 2 Therefore the expression myArr 2 is for all purposes like a variable of type int Notice that the third element of myArr is specified myArr 2 since the first one is myArr 0 the second one is myArr 1 and therefore the third one is myArr 2 By this same reason its last element is myArr 4 Therefore if we write myArr 5 we would be accessing the sixth element of myArr and therefore exceeding the size of the array In C it is syntactically correct to exceed the valid range of indices for an array This can create problems since accessing out of range elements do not cause compilation errors but can cause runtime errors The reason why this is allowed will be seen further
52. out of the scope of the loop into program scope The output is printed on console as The factorial of 0 is 24 Workout yourself Though the above factorial code snippet has executed nicely and produced correct and valid result of factorial of 4 i e 24 but while prompting output to user it wrongly says that factorial of 0 is 24 It must show that factorial of 4 is 24 Find out the reason for the above misprinting and correct the program by modifying the code so that it produces expected output prompt to user Check your result with your teacher Why my do while loop is getting executed once even when the condition is not satisfied It is very important to understand here that in do while loop the looping condition is evaluated at the end of the loop s scope i e after the last statement in the scope of loop This type of checking is called Exit Control Checking if the condition fails this checking it will not be allowed into the scope of the loop on next iteration cycle In the whole affair you are observing that the loop had executed at least once even when condition fails in 1 Iteration cycle That is why do while loops are often called as Exit Control Loop You can imagine a similar checking situation that your shopping bag items and purchase bill are being checked on your exit out of a shopping mall where you have been for shopping For example consider the program 2 3 ahead Sentinels O
53. programmer circuit When the EPROM is in use then it behaves like a ROM that means the information can only be read Electrically Erasable Programmable Read Only Memory EEPROM The contents of this type of ROM can be erased and then reprogrammed using electric signals This makes it an excellent back up for RAM whose contents are lost when the power is switched off When the power is returned the contents of EEPROM are copied back into the RAM and the computer continues working without any data loss Nowadays RAMs and EEPROM sS are integrated in a single chip Cache Memory Cache memory is a special high speed memory made up of high speed static RAMs It is used to hold frequently accessed data and instructions We know that the processing spleed of CPU is much more than the main memory access time of the computer This means the CPU has to wait for a substantial amount of time Alternatively we have the cache memory which is a small expensive but fast memory that is placed between the CPU and the main memory Whenever some data is required the CPU first looks into cache If data is found we call it a cache hit and the information is transferred to the CPU In case of a miss the main memory is accessed Memory caching proves to be efficient because most programs repeatedly access the same data and instructions so access of aui used data becomes very fast with cache memory There are two types of M cache memory amp L1 cache It is small
54. relatively inexpensive and faster computers these days were found in areas of education small businesses and offices along with industrial and business applications IBM 360 was a very popular third generation computer Examples IBM 360 series Honeywell 6000 series The Fourth Generation 1975 onwards In this generation Large Scale Integration LSI and Very Large scale integration VLSI technology was used by which up to 300 000 transistors were used on a single chip Thus integration of complete CPU on a single chip was achieved in 1971 and was named microprocessor which marked the fourth generation of computers The computers based on microprocessor technology had faster accessing and processing speeds In addition to this the increased memory capacity further made the computers more powerful and also more efficient operating systems were developed for these computers New concepts of microprogramming application software databases virtual memory etc were developed and used The computers that we use today belong to this generation These portable computers can be carried from one place to another owing to their compact size They are much more accurate Even memory sizes have become phenomenal Commercial production of these computers is easier and they are the least expensive compared to the earlier generation computers Also computer networks starting coming up during this generation It is today one of the most popular means to interact a
55. studied till now will only enable you to write simple linear programs or sequential programs 1 1 2 Linear Flow A simple linear program is one which has a linear flow of execution of programming logic statements e g program 1 1 The logic of program flows or better they are termed as control flow from top to bottom out of set of statements Now let us proof the that program 1 1 follows a sequential flow of logic by the following flow chart diagram flowchart 1 Declare a and b as variables Input a and b Calculate a b and print sum So easy isn t it As you observe that the arrows are moving in one direction only from top to bottom the flow of program is sequential linear Work out yourself Identify few of the programs which you have written while dealing Unit 3 and find whether they are following sequential flow of program If yes can you make a flow chart to justify your idea So there exist a big question now that whether C programs have other types of flow of program which is totally different from linear flow Yes students we also have other types of flow of program Conditional Flow Let us investigate the real life problems visited by us earlier in this chapter a Ram needs to find out whether a number is divisible by both 3 and 5 We will represent the above problem in flow chart notation flowchart 2 Path2 Path 3 Observe the above flowchart 2 and compare it with the earlier flo
56. subtraction operations was performed by controlled rotation of these wheels Leibnitz s Calculator In 1673 Gottfried Leibnitz a German mathematician extended the capabilities of the adding machine invented by Pascal to perform multiplication and division as well The multiplication was done through repeated addition of numbers using a stepped cylinder each with nine teeth of varying lengths Jacquard s Loom In order to make the cotton weaving process automatic Joseph Jaquard devised punch cards and used them to control looms in 1801 The entire operation was under a program s control Through this historic invention the concept of storing and retrieving information started Difference engine and Analytical Engine Charles Babbage an English mathematician developed a machine called Difference Engine in 1822 which could calculate various mathematical functions do polynomial evaluation by finite difference and theoretically could also solve differential equations Thereafter in 1833 he designed the Analytical Engine which later on proved to be the basis of modern computer This machine could perform all the four arithmetic operations as well as comparison It included the concept of central processor memory storage and input output devices Even the stored information could be modified Although the analytical engine was never built that time but Babbage established the basic principles on which today s modern computers work
57. transfer data rapidly from one electronic device to another The FireWire port yp teen has the ability to interact with a number of different devices since it provides a single plug and socket con nection for all devices A FireWire port can provide La C an ideal way to connect a scanner and digital camera camcorder to a computer lt system as the data transfer is relatively faster than on USB and also results in imee excellent quality UNIT 2 Introduction to C C CHARACTER SET Character set is asset of valid characters that a language can recognize A character can represents any letter digit or any other sign Following are some of the C character set LETTERS AtoZ and atoz DIGITS 0 9 SPECIAL SYMBOLS A ale lt gt amp F WHITE SPACE Blankl space horizontal tab gt carriage return Newline Form feed OTHER CHARACTERS 256 ASCII characters as data or as literals TOKENS The smallest lexical unit in a program is known as token A token can be any keyword Identifier Literals Puncutators Operators KEYWORDS These are the reserved words used by the compiler Following are some of the Keywords auto continue float new signed volatile short long class struct else inline delete friend private typedef void template catch friend sizeof union register goto IDENTIFIERS An arbitrary name consisting of letters and digits to identify a particular word C is case sensitive as nit treats u
58. which is true the flow of control then proceeds in the similar way as it did in the first iteration and this is repeated till the looping condition becomes false i e when i will become equal to 4 Let us put all the things discussed above in the form of an iteration tracking table Iteration i Looping condition Output Starting of loop 0 lt 3 true Arun Kumar Kamal Kant Gupta Anil Kumar End of 1 Iteration i 1 lt 3 true Same as above End of 2 Iteration i 2 lt 3 true Same as above 96 End of 3 Iteration i 3 lt 3 true Same as above End of 4 Iteration i 4 lt 3 false No entry into for block loop is terminated Observe the above table carefully to find that the loop has executed for 4 times and the last value of the iterative variable on the termination of loop is 4 Variations in for loop All the three parts of a for loop are optional part i e they may or may not be present Observe the valid variation in syntax of for loop variation 1 int i 0 for is 9 i cout lt lt Hello to all In the above for loop the first part has been left i e we have not declared and initialized the iterator in for though it has been declared outside the scope of for variation 2 inti 0 for i if i lt 5 cout lt lt Hello to all else break In the above variation 2 t
59. 4bytes 3 4e 38 7 digit 3 4e 38 7 digits Double precision floating point i i 2 m lang aauna I o ae PRTA Pegang Poimi 1 7e 308 15 digits Derived Data Types The datatypes which are extracted derived from fundamental data types are called derived datatypes These datatypes can be derived by using the declaration operator or punctuators for e g Arrays function Pointer Class Structure union etc Class A class represents a group of similar objects To represent class in C it offers a user defined datatypes called CLASS Once a Class has been defined in C Object belonging to that class can easily be created A Class bears the same relationship to an object that a type does to a variable Syntax of CLASS Class class_name Private Data members 1 Data members n Member functions 1 Member functions n Public Data members 1 Data members n Member functions 1 Member functions n end of class Class name object of Class creating an object of class Private and Public are the access specifiers to the class STRUCTURE A Structure is a collection of variables of different data types referenced under one name It also may have same data types The access to structure variables is by default global i e they can be accessed publicly throughout the program Syntax of structure struct structure_name Structure variable 1 Structure variable n end of structure Struc
60. ISCII Indian scripts Standard Code for Information Interchange and UNICODE for multilingual computing Microprocessor Basic concepts Clock speed MHz GHz 16 bit 32 bit 64 bit processors 128 bir processors Types CISC Processors Complex Instruction set computing RISC Processors Reduced Instruction set computing and EPIC Explicitly parallel Instruction computing Memory Concepts Units Byte Kilo Byte Mega Byte Giga Byte Tera Byte Peta Byte Exa Byte Zetta Byte Yotta Byte Primary Memory Cache RAM ROM Secondary Memory Fixed and Removable storage Hard Disk Drive CD DVD Drive Pen Drive Blue Ray Disk Input Output Ports Connections Serial Parallel and Universal Serial Bus PS 2 port Infrared port Bluetooth Firewire UNIT 2 INTRODUCTION TO C 44 Theory 36 Practical Periods Getting Started C character set C Tokens Identifiers Keywords Constants Operators Structure of a C Program include files main function Header files iostream h iomanip h cout cin use of I O operators lt lt and gt gt Use of endl and setw Cascading of I O operators Error Messages Use of editor basic commands of editor compilation linking and execution Data Types Variables and Constants Concept of Data types Built in Data types char int float and double Constants Integer Constants Character constants n t b Floating Point Constants String Constants Access modifier const V
61. Parr Aaaa Aor HAS HAT SZ FE mi a tho fea re STUDY SUPPORT MATERIAL Reviewed Revised 2013 14 ma CLASS XI aAA AAT COMPUTER SCIENCE 083 KENDRIYA VIDYALAYA SANGTHAN MUMBAI REGION 1 ACKNOWLEDGEMENTS CHIEF PATRON SHRI AVINASH DIKSHIT COMMISSIONER KENDRIYA VIDYALAYA SANGATHAN NEW DELHI PATRON MS R KALAVATHI DEPUTY COMMISSIONER KENDRIYA VIDYALAYA SANGATHAN BHUBANESWAR REGION ADVISORS SHRI M V R K SASTRY ASSISTANT COMMISSIONER KENDRIYA VIDYALAYA SANGATHAN BHUBANESWAR REGION SHRI G S N REDDY ASSISTANT COMMISSIONER KENDRIYA VIDYALAYA SANGATHAN BHUBANESWAR REGION CO ORDINATOR SHRI S K CHOPDAR ASSISTANT COMMISSIONER KENDRIYA VIDYALAYA SANGATHAN BHUBANESWAR REGION STUDY MATERIAL PREPARATION COMMITTEE CONVENER MEMBERS SHRI S K BEHURA PRINCIPAL KENDRIYA VIDYALAYA NO 1 UNIT IX BHUBANESWAR SH ARUN KUMAR PGT COMP SC KV NO 1 2P SHIFT BHUBANESWAR SH KAMAL KANT GUPTA PGT COMP SC K V NO 2 SV NAGAR VSKP SH ANIL KUMAR SS PGT COMP SC K V NO 1 SV NAGAR VSKP SH MUNENDRA PRAKASH PGT COMP SC K V WALTAIR VSKP PREFACE Kendriya Vidyalayas are pace setting institutions spread across the length and breadth of this vast country including a few in the foreign lands Text books are like the sumptuous meals but a few students do need a digestive tablets to digest the food The condensed versions of the text books is what the
62. a Sangathan Human Resource and development 2 The Setw Manipulator The setw manipulator causes the number or string that follows it in the stream to be printed within a field n characters wide where n is the arguments to setw n Increment and Decrement Operators in C The increase operator and the decrease operator increase or reduce by one the value stored in a variable They are equivalent to 1 and to 1 respectively Thus C C 1 C C 1 are all equivalent in its functionality the three of them increase by one the value of C A characteristic of this operator is that it can be used both as a prefix and as a suffix That means that it can be written either before the variable identifier a or after it a Although in simple expressions like a or both have exactly the same meaning in other expressions in which the result of the increase or decrease operation is evaluated as a value in an outer expression they may have an important difference in their meaning In the case that the increase operator is used as a prefix a the value is increased before the result of the expression is evaluated and therefore the increased value is considered in the outer expression Example 1 B 3 A B here A contains 4 B contains 4 In case that it is used as a suffix a the value stored in a is increased after being evaluated and therefore the value stored before the increase operation is evaluated in
63. a nested for with suitable example Q No 4 a Write a program to print the diagonal left amp right elements of an NUN matrix A Program to print the left and right diagonal element of an NXN matrix include lt iostream h gt include lt conio h gt include lt iomanip h gt void main int A 10 10 int i j N clrscr cout lt lt nHow many rows and columns required for matrix cin gt gt N cout lt lt nEnter lt lt N N lt lt elements for i 0 i lt N i cout lt lt Enter the elements into Row lt lt i 1 lt lt for j 0 j lt N j cin gt gt Ali i clrscr cout lt lt nThe entered elements in the matrix are n for i 0 i lt N i for j 0 j lt N j cout lt lt Ali j lt lt t cout lt lt endl cout lt lt n n nThe elements which are belongs to only diagonals n for i 0 i lt N i for j 0 j lt N j if i J i j N 1 cout lt lt setw 6 lt lt A i j else cout lt lt cout lt lt endl getch b Write a program to find the factorial of a number recursive function A include lt iostream h gt include lt conio h gt long f 1 long factorial int n if n 0 return f else f n factorial n 1 void main clrscr long num cout lt lt nEnter the number to which you want to find factorial cin gt gt num cout lt lt nThe factorial of the number lt lt factorial num getch c
64. ain module and its related module Each module should also be divided into sub modules according to software engineering and programming style The division continues till the module consists only of an elementary process that is intrinsically understood and cannot be further sub divided Bottom up design Bottom up design is just the opposite of top down design It refers to a style of programming in which an application is constructed with existing primitives of the programming language and then gradually more and more complicated features are added till applications are written In other words initiating the design with simple modules and then build them into more complex structures ending at the top is bottom up design Designing the problem Designing the problem can be expressed in the form of Algorithm Flowchart Algorithm An algorithm is a set of instructions that describe a method for solving a problem It is normally given in mix of computer code and English language This is often called pseudo code Flowchart The algorithm is represented in the form of a diagram with action boxes linked by lines showing the order in which they are executed This is known as the flow of control It is the diagrammatic representation of an algorithm Coding The process of translating the algorithm into syntax of a given language is known as Coding Since algorithm cannot be executed directly by the computer it has to be translat
65. al else cout lt lt nRoots are complex ie Imaginary d1 b d 2 a d2 b d 2 a cout lt lt nD1 lt lt d1 cout lt lt nD2 lt lt d2 getch Sample Paper III Subject Computer Science Time 3Hours Maximum Marks 70 Note i All questions are compulsory Q No 1 Define Analog an Digital Computer why analytical engine often called the pioneer computer what are the different types of printer Explain in brief What is the difference between copying and moving files and folders What functions are performed by an operating system as a resource manager Define the term ASCII and ISCII What are the different Data representation schemes Explain different types of RAM What do you mean by ports Explain in brief all types of ports 4 Why primary memory is termed as destructive write memory but non destructive read memory Explain the different features of OOP 3 Q No 3 a Find the output of the following program include lt iostream h gt void Withdef int HisNum 30 for int I 20 l lt HisNum 1 5 cout lt lt I lt lt cout lt lt endl void Control int amp MyNum MyNum 10 Withdef MyNum void main int YourNum 20 Control YourNum Withdef cout lt lt Number lt lt YourNum lt lt endl b void main char NAME a ProFiLe for int x 0 x lt strlen NAME x if islower NAME x NAME x toupper NAME x
66. amount of related information about similar entities like WORKER To solve the given problem using C Structure one has to bundle all the information related to a single WORKER under one single tag name This Bundle of information related to an entity with a Tag Name is called Structure 127 Hari kajri se Bajrangi Bundled together to form a structure having data related to the worker RAMU M F Let us now have a look at the syntax for creating a structure A Structure in C is created by using the Keyword struct The General Syntax for creating a Structure is Syntax struct lt Name of Structure gt lt datatype gt lt data member 1 gt lt datatype gt lt data member 2 gt lt datatype gt lt data member 3 gt lt datatype gt lt data member n gt lt variable list gt Example A Proper example following the previous syntax could be struct Structure name ar name 45 char gender data member int age float rate m structure variable representing 3 workers Points to remember 1 A structure can declared locally inside main or globally Outside main local declaration main struct WORKER char name 45 char gender W1 W2 W3 In this case we can create structure variable only within main Global declaration struct WORKER char name 45 char gender
67. ansfer the control out of the loop for ae if true false condition break here the control is transferred to here continue makes the compiler to execute the next iteration of the loop for Condition continue will not b executed and next iteration will happen continue can be given inside an if condition e toj Do yourself include lt iostream h gt include lt conio h gt include lt iomanip h gt void main int A 10 10 int i j N clrscr cout lt lt nHow many rows and columns required for matrix 146 cin gt gt N cout lt lt nEnter lt lt N N lt lt elements for i 0 i lt N i cout lt lt Enter the elements into Row lt lt i 1 lt lt for j 0 j lt N j cin gt gt ALi fj clrscr cout lt lt nThe entered elements in the matrix are n for i 0 i lt N i for j 0 j lt N j cout lt lt A i j lt lt t cout lt lt endl cout lt lt n n nThe elements which are belongs to only diagonals n for i 0 i lt N i for j 0 j lt N j if i J i j N 1 cout lt lt setw 6 lt lt A i j else cout lt lt cout lt lt endl getch b include lt iostream h gt include lt conio h gt long f 1 long factorial int n if n 0 return f else f n factorial n 1 void main clrscr long num cout lt lt nEnter the number to which you want to find factorial
68. ariables of built in data types Declaration Initialization of variables Assignment statement Type modifier signed unsigned long Operator and Expressions Operators Arithmetic operators Unary operator Increment and Decrement Operators Relation operator gt gt lt Logical operators amp amp II Conditional operator lt condition gt lt if false gt Precedence of Operators Automatic type conversion in expressions Type casting C shorthands UNIT 3 PROGRAMMING METHODOLOGY 28 Theory 10 Practical Periods General Concepts Modular Approach Clarity and Simplicity of Expressions Use of proper names for Identifiers Comments Indentation Documentation and Program Maintenance Running and Debugging programs Syntax Errors Run Time Errors Logical Errors Problem solving Methodologies Understanding of the problem solution for the problem identifying minimum number of inputs required for output writing code to optimizing execution time and memory storage step by step solution for the problem breaking down solution into simple steps modular approach identification of arithmetic and logical operations required for solution Control Structure conditional control and looping finite and infinite Problem Solving Introduction to Algorithms Flowcharts UNIT 4 PROGRAMMING IN C 50 Theory 48 Practical Periods Flow of control Conditional statements if else Nested
69. array name into the parameter of the function cout lt lt You have inputted your name as puts myname isalnum isalpha isdigit checks whether the character which is passed as parameter to them are alphanumeric or alphabetic or a digit 0 to 9 If checking is true functions returns 1 program 3 2 program to use isalnum isalpha isdigit include lt iostream h gt include lt ctype h gt void main char ch cout lt lt Input a character cin gt gt ch if isdigit ch 1 cout lt lt The inputed character is a digit else if isalnum ch 1 cout lt lt The inputed character is an alphanumeric else if isalpha ch 1 cout lt lt The inputed character is an alphabet islower isupper tolower toupper islower checks whether a character has lower case isupper does opposite tolower converts any character passed to it in its lower case and the toupper does opposite program 3 3 program to use islower isupper tolower toupper include lt iostream h gt include lt ctype h gt void main char ch cout lt lt Input a character cin gt gt ch if isupper ch 1 checks if character is in upper case converts the character to lowercase tolower ch cout lt lt ch else if islower ch 1 checks if character is in lower case converts the character to Il uppercase toupper ch cout lt
70. at for example we can store 5 values of type int in an array without having to declare 5 different variables each one with a different identifier Instead of that using an array we can store 5 different values of the same type int for example with a unique identifier For example an array to contain 5 integer values of type int called myArr could be represented like this 0 2 3 4 where each blank panel represents an element of the array that in this case are integer values of type int These elements are numbered from 0 to 4 since in arrays the first index is always 0 independently of its length Like a regular variable an array must be declared before it is used A typical declaration for an array in C is Syntax lt datatype gt array_name elements where datatype is a valid type like int float name is a valid identifier and the elements field which is always enclosed in square brackets specifies how many of these elements the array has to contain Therefore in order to declare an array called myArr as the one shown in the above diagram it is as simple as int myArr 5 NOTE The elements field within brackets which represents the number of elements the array is going to hold must be a constant value since arrays are blocks of non dynamic memory whose size must be determined before execution In order to create arrays with a variable length dynamic memory is needed which is e
71. ata in a database We can also import and export the data to many formats including Excel Outlook ASCII dBase FoxPro Oracle SQL Server ODBC etc Popular examples of Database Management System are Base Open Office and Microsoft Access Customized Software Customized Software is one which is tailor made as per the user s requirement Such type of software is customer specific It is made keeping in mind the individual needs of the user and so are also referred as Domain Specific Tools Such software cannot be installed and used by any other user customer since the requirements may differ Some examples of customized software are discussed below x Inventory Management System amp Purchasing System Inventory Management System is generally used in departmental stores or other organizations to keep the record of the stock of all the physical resources For Example in a Computer store it keeps record of the number of computers printers printing sheet printer cartridge available It also helps to place purchase orders bills invoices etc Various reports as to position of stock sales made in a particular period profit earned etc can be generated x School Management System School Management System sometimes called a School Information System or SIS is a system that manages all of a school s data in a single integrated application Having all of the information in a single system allows schools to more easily connect data together
72. ata to the output device and in the meantime the program fills another buffer This technique is called overlapped processing This is because while the operating system reloads one buffer the executing program doesn t stop as it is able to retrieve fill data from in another buffer Spooling Simultaneous Peripheral Operation on Line This is a device management technique used for processing of different tasks on the same input output device Say for example there are various users on a network sharing the same printer At one point of time more than one user might give print command The speed of the printer is very slow as compared to the CPU processing So the operating system temporarily stores the data of every user on the hard disk of the computer to which 20 the printer is attached The individual users need not wait for the printing process to be complete Instead the operating system sends the data from to hard disk to the printer one by one x Memory management In a computer both the CPU and the I O devices interact with the memory When a program needs to be executed it is loaded onto the main memory till the execution is complete Thereafter that memory space is freed and is available for other programs The common memory management techniques used by the operating system are Partitioning and Virtual Memory Partitioning The total memory is divided into various partitions of same size or different sizes This helps to accommo
73. b Assuming suitable data types give necessary declaration for an array of 20 voter records each record of which consists of four data values viz id_no name address age make use of above declaration to write program segment that print id_no and name for all those whose age exceeds 60 c Write a program to add two matrices of same order MXN d Write a program to find either given no is prime or not e Write a function to find simple interest Sample Paper V Subject Computer Science Time 3Hours Maximum Marks 70 Note i All questions are compulsory Q No 1 a Write the header file for the given function abs isdigit sqrt setw b Define Microcomputer c what is data and what is the output of data processing system d what is the function of memory and what are its measuring units e what do you mean by language processor f what is the difference between save and save as command g Expand the following i CPU ii ROM iii MICR iv CD R 2 Q No 2 a Rewrite the following code after removing the syntax error if any Underline the correction include lt iostream h gt jampto int int void main first 10 second 20 jumpto first second jumpto second void jumpto int n1 intn2 20 n1 n1 n2 b Find the output void result int amp x int y 10 int temp x y x temp if y lt 10 y temp void main int A1 10 B2 5 result A1 B2 cout lt lt A1 lt lt B2 l
74. binary 1A8 A8 16 gt X 2 0001 1010 1000 1010 1000 Binary Representation of Integers Binary number can be represented only by using 0 s and 1 s but can not use the sign to denote the negative number or sign to denote the positive number So it must be either 0 or 1 There are three methods to represent binary number They are i Sign and magnitude method 11 One s complement method 111 Two s complement method Sign and magnitude method In this method first bit is considered as a sign bit Here positive number starts with 0 and negative number starts with 1 Example 25 25 2 12 12 2 6 6 2 3 3 2 1 1 2 0 1 So the binary number is 11001 2 If we take the size of the word is 1 byte then the number 25 will be represented as 00011001 Suppose if the number is 25 and then it will be represented as 10011001 One s Complement Method In this method the positive number is represented as same as the binary number If the number is negative then we need to find one s complement of a binary number The one s complement of a binary number will replace every 0 with 1 and vice versa Example i Represent 86 in one s complement method I byte representation 86 2 43 43 2 21 21 2 10 10 2 5 5 2 2 2 2 1 1 2 0 1 The binary number is 1010110 1 byte representation of number 86 is 01010110 11 Represent 86 in one s complement method I byte representation The given numb
75. ble A monolithic system does not have any parts or modules from top to bottom it is one piece Software industry has also adopted the modular approach of design where a big software is divided into several modules Each of the modules are designed for performing specialized task in the whole software These modules interact with other modules of the system to carry out essential functionality of the whole system Each module during its course of execution repeats same type of task so whenever the whole system requires a specific type of task for which a particular module is responsible it calls or invokes that module and the task is done This calling of module to perform a certain action can be done several number of times while the software as a whole executes Let us understand the above concept with the help of a real life example Suppose our KVS is going to develop a centralized software for managing all Kvs across the country While designing such a software KVS has to divide the whole operation of the software into three big modules called as Admin Academic and Accounts each of these modules could be again broken down into many simple and small sub modules like Admin Module can have Admission Construction Recruitment etc whereas the Academics can again have sub modules like Student Registration Examination Results etc 101 The following diagram describes the whole concept very easily KVS Management Software
76. ble local to for loop only You will follow the turbo c type scoping The second part of a for loop defines the looping condition using set of relational and logical operators and governs the number of times the loop would execute This looping condition is checked before entering into loop for e g i lt j k etc The third part of the for loop defines how to change the value of iterative looping variables with each cycle This is very important as to execute the loop for a fixed number of times for e g i j j k etc Let us now integrate all the above three parts to observe how a for loop works Example The above loop starts with declaring variable i 0 then it proceeds to the looping condition part to check whether condition is satisfied evaluates as true so that the flow could enter into the scope of the loop i e 0 lt 3 which is true the control flow is allowed to enter into the scope of the loop and all the statements the 3 lines gets executed one after another After executing the last statement within the scope of for the control proceeds to the third part of the loop where it increments the value of looping variable i by 1 so that the variable is getting the next consecutive higher value i e i 1 Hence the first Iteration of the for loop is finished Now at the start of the next iteration the control flow directly proceeds to the second part of the for loop to evaluate looping condition i e 1 lt 3
77. can be checked amp Reservation System Reservation System is software used to book reserve air flights railway seats movie tickets tables in a restaurant etc In the case of a booking system the inputs are booking requests The processing involves checking if bookings are possible and if so making the bookings The outputs are booking confirmations rejections amp Weather Forecasting system This software makes it possible to forecast the weather for days and even months in advance The detailed weather reports can also be generated Open Source Concepts Software are mainly categorised into the following categories based on their licenses 1 Proprietary 2 Shareware 3 Freeware 4 Open source 5 Free Software amp Proprietary We pay a supplier for a copy of the software which these days may be supplied on physical media disks or downloaded from the Internet We get the permission to use the software on one or sometimes more than one machines Examples of this type of software include Microsoft Office and Microsoft Windows x Shareware Shareware is basically a software for trial purpose that the user is allowed to try for free for a specified period of time It is usually downloaded from the Internet When the trial period ends the software must be purchased or uninstalled x Freeware Freeware software is free of cost and is usually bundled up with some operating system or any other software Examples of freewa
78. chart 2 given earlier Try to answer the following question a Are directions of arrows in both flowchart 2 and 3 are always pointing downwards Yes No 69 b If your answer to the above question a is in No then what are other directions in which arrows proceeds choose from Leftwards Rightwards Upwards all of them c In which flowchart the arrow proceeded upwards and Why Verify your answer with your teacher Sometime according to special problem situation we find that in a program we proceed to a same statement step again which we have visited earlier during flow of program Observing flowchart 2 we find that we never proceed to a step twice In case of flowchart 3 we observe that steps after the rhombus are repeated if logic in rhombus produces a Yes value you may see that an arrow moves upwards to the rhombus A cycle is formed between the Rhombus and steps after it based on the Yes value of the logic n lt 40 kept in rhombus This cyclic path of execution is referred as an Iteration in C programming jargon Workout yourself i How many times the program proceeds in a Cyclic path in the flowchart 3 Why When does this cyclic path of execution ends in the flowchart 3 ii What will happen if the cyclic path of execution never gets ended The cyclic path of execution or Iteration in problem represented by flowchart 3 ends based on the No value of the logic n lt 40 kept in rhomb
79. ck and while loop is terminated Thus coming out of while loop block the value of sum is printed as 10 loop executes for 4 times Workout yourself Consider the program given below void main intx 5 m 1 p 0 while p lt 50 p x m m Now complete the following Iteration tracking table with details of each iteration the first one is done for you Iteration loop condition 1 Iteration 0 lt 50 gt true Check it out with your teacher Why my while loop is not getting executed It is very important to understand here that in while loop the looping condition is evaluated at the beginning of the loop s scope i e prior to the entering into scope of loop This type of checking is called Entry Control Checking if the condition fails this checking it will not be allowed into the scope of the loop That is why while loops are often called as Entry Control Loop You can imagine a similar checking situation that your tickets are being checked prior to your entry into a cinema hall to view a film You will not be able to view the film at all if you don t have the tickets Similarly if the loop condition fails at the first time itself the statements under the scope of loop will not run even once Observe such a code scenario below noOfPersons 4 noOfTickets 3 while noOfTickets gt noOfPersons cout lt lt Welcome to Gangs of C
80. curly braces The statement kept under simple if gets executed only when the conditional expression logical statement under it is evaluated as true Examples intx 1 y 3 X y if x gt y cout lt lt x is greater In the above example the conditional statement under if will be always evaluated as true because the value of x will become 4 before the comparison thus the expression 4 gt 3 yields a true value letting the statement under if to execute i e the output of the above code snippet would be x is greater Workout yourself Convert the above code snippet into a program in your practical period and execute it verify the output Now change the initial value of x to 0 instead of 1 i e Change x 0 in the program Execute the 2 1 2 Compound If if else combination syntax if lt conditional statement gt statements to be executed when logical statement is satisfied Il i e when the logical statement yields a true value else statements to be executed when logical statement is not satisfied i e when the logical statement yields a false value Example intx 0 y 3 X y if x gt y cout lt lt x is greater else cout lt lt we are in else part because x and y both became equal The above code snippet portion has two different paths of execution If the conditional statement under if is evaluated to b
81. d the highest case value being the last case They can exist in any order e The default case is optional and should be always kept at the last place in switch case construct f A switch case construct can also be nested within another switch case operator Workout yourself i Write a program which inputs a month number from user and then finds the total days present in that month Use only switch case construct For example if user inputs month number as 2 then the program displays February has 28 or 29 days ii Compare and contrast switch case construct with ladder if else if construct in a tabular form 2 1 6 Conditional operator lt gt lt gt lt gt Conditional Operator is a small short hand operator in C which helps to implement flow of logic based on some condition like if else construct The syntax of the conditional operator is Syntax lt logical expression gt lt true part gt lt false part gt The logical expression in the operator gets evaluated either as true or false if true then statement after symbol gets executed otherwise statement after symbol gets executed It acts much like an if else construct but can only execute single statement Like if else the conditional operator 86 cannot have a block of code to execute in its true or false part We often use conditional operator to implement a short one line conditional expression Example intx 5 y 7 int res
82. date number of programs in the memory The partition can be fixed i e remains same for all the programs in the memory or variable i e memory is allocated when a program is loaded on to the memory The later approach causes less wastage of memory but in due course of time it may become fragmented Virtual Memory This is a technique used by the operating system by virtue of which the user can load the programs which are larger than the main memory of the computer In this technique the program is executed even if the complete program is not loaded on to the main memory The operating system divides the main memory into equal sizes called pages A part of the program resides in the main memory and is called the active set The rest is in the secondary storage device in the form of tracks sectors or blocks With the help of Page Map Tables PMT the operating system keeps track which page of main memory is storing which block of secondary memory A virtual address which is not the real physical address is mapped either to the main memory or the secondary memory Hence virtual memory allows more programs and even larger programs to be executed in the main memory leading to efficient memory utilization x File Management The operating System manages the files folders and directory systems on a computer Any data on a computer is stored in the form of files and the operating system keeps information about all of them using File Allocation Table FAT T
83. disk destroy file allocation tables and cause the system to hang Worm Worm is a program capable of replicating itself on a computer network A worm also does not require a host as it is a self contained program They generally travel from one computer to another across communication links on a network They generally disrupt routine services x Disk Defragmenter The memory is used in small chunks randomly Sometimes when a memory chunk of appropriate size is not available the operating system breaks or fragments the files resulting in slower access to files A disk defragmenter scans the hard disk for fragmented files and brings all the fragments together x Backup Utility This utility is used to create the copy of the complete or partial data stored in a disk or CD on any other disk In case the hard disk crashes or some other system failure occurs the files can be restored using backup software amp Compression Utility This utility is used to compress large files Compression is useful because it helps reduce resources usage and the file transmission on the network becomes easier x Disk Cleaner This utility scans for file that have not been accessed used since long Such files might be occupying huge amount of memory space In that case the Disk Cleaner utility prompts the user to delete such 24 files so as to create more space on the disk If the files are important the user might take a backup before deleting them x Fi
84. dlib h randomize random itoa atoi The above list is just few of the header files and functions available under them but actually there are many more If you want to learn their use go to the help menu of your turbo C compiler and search out function list and learn its prototype The calling of library function is just like User defined function with just few differences as follows i We don t have to declare and define library function ii We must include the appropriate header files which the function belongs to in global area so as these functions could be linked with the program and called Library functions also may or may not return values If it is returning some values then the value should be assigned to appropriate variable with valid datatype Let us deal with each of these library functions by calling the them from programs gets and puts these functions are used to input and output strings on the console during program run time gets accept a string input from user to be stored in a character array puts displays a string output to user stored in a character array program 3 1 program to use gets and puts include lt iostream h gt include lt stdio h gt must include this line so that gets puts could be linked and called void main char myname 25 declaring a character array of size 25 cout lt lt input your name gets myname just pass the
85. e Write an algorithm to print all natural numbers up to n Step 1 Start Step 2 Take any number and store it in n Step 3 Store 1 in I Step 4 Check I value if I lt n then go to step 5 else go to step 8 Step 5 Print I Step 6 Increment I value by 1 Step 5 Go to step 4 Step 8 Stop In the above example steps 4 5 6 and 7 are executed more than one time Flowchart In the previous section of this chapter we have learnt to write algorithms i e step by step process of solving a problem We can also show these steps in graphical form by using some symbols This is called flowcharting Flowchart Symbols Symbol Function An oval repress a Start ar ond pein A line 1s a commecbor that shows af aged ek thi Fepresenialive shapes Inpad Oulput A parallelogram represents input ar auptut Becizion A diamond indicates a decision A cectanphe negresents 1 process The following flowchart is an example of a sequential execution begin Sequential Statement 1 Statement 2 Statement 3 end 3 The following flowchart is an example of a selective execution Programming Methodology After studying this lesson the students will be able to amp understand the need for good programs amp understand how to solve problems using different ways x get clear idea about problem solving methodology and amp understand the types of errors normally occur while writing programs Introduction Learn
86. e Its format is condition result1 result2 e g 7 5 4 3 _ returns 3 since 7 is not equal to 5 Comma operator The comma operator is used to separate two or more expressions that are included where only one expression is expected When the set of expressions has to be evaluated for a value only the rightmost expression is considered For example the following code a b 3 b 2 Would first assign the value 3 to b and then assign b 2 to variable a So at the end variable a would contain the value 5 while variable b would contain value 3 Explicit type casting operator Type casting operators allow you to convert a datum of a given type to another There are several ways to do this in C The simplest one which has been inherited from the C language is to precede the expression to be converted by the new type enclosed between parentheses int i float f 3014 i int f The previous code converts the float number 3 14 to an integer value 3 the remainder is lost Here the typecasting operator was int Another way to do the same thing in C is using the functional notation preceding the expression to be converted by the type and enclosing the expression between parentheses i int f Both ways of type casting are valid in C sizeof This operator accepts one parameter which can be either a type or a variable itself and returns the size in bytes of that type or object a size
87. e increment is reflected back in actual parameter Similarly if we don t want to pass our structure variable as reference we can do so but then we have to return the modified structure variable back This can be achieved in above function if we take return type as structure name Let us modify the function so that it returns a structure Worker increaseWage Worker w float incr if w gender F w gender f return W 4 2 6 Use of typedef statement A typedef can be used to indicate how a variable represents something This means that we are defining another name for an existing datatype Let us see the following example to understand this w wage w wage incr 100 Suppose we are going to write a program in C where we need lot of strings of size 30 say This means that every time we have to declare character array of size 30 like char arr 30 or so Instead of declaring each time with size specification if we have a declaration like string arr which automatically instructs the compiler that arr will be a character array of size 30 then this will give a good look to our program We can achieve this by using typedef statement as done in the program given below include lt iostream h gt typedef char string 30 main string name cout lt lt Input your name gets name cout lt lt You name has lt lt strlen name lt lt ciharacters The s
88. e true then the statement under if block will be executed otherwise the statements under else block would be executed The above code produces an output as we are in else part because x and y both became equal because the conditional statement under if evaluates as false as x is not greater than y it is same as that of y Workout yourself In the above code snippet modify the logical statement under if such that the if block gets executed instead of else block You should not modify the initial values of x and y or change number of variables in the program 2 1 3 Complex If if else ladder do something if condition 2 is satisfied else if lt condition 3 gt do something if condition 3 is satisfied many more n 1 else if ladder may come else if lt condition n gt do something if condition n is satisfied at last do here something when none of the above else if conditions gets satisfied In the above syntax there are ladder of multiple conditions presented by each if all of these conditions are mutually exclusive that is only one of them would get satisfied and all the conditions below it would not be evaluated and is discarded Say suppose if condition 3 gets satisfy i e it yields a true value for the condition the statement under the block of third if gets executed and all other n number of if conditions below it would be discarded
89. ead only memory Random Access Memory RAM In case of RAM the memory can be accessed from any desired location randomly That means without searching the entire memory any location can be accessed in the same amount of time The instructions and data that we input into the computer are stored in the RAM of the Computer It is a read write memory so data can be both read from and written to the RAM It is a volatile memory and loses its contents when the power is switched off or interrupted Nowadays RAMs are available in gigabytes The normal memory access time of a RAM is 20 80 ns RAM can be broadly classified into two categories Dynamic RAM DRAM and Static RAM SRAM Dynamic RAM DRAM It consists of a transistor and a capacitor that stores electric charge The DRAMs are physically smaller cheaper and slower memories They are slower because the data stored in them needs to continuously refreshed and this consumes lot of processor time Each refresh operation takes several CPU cycles to complete This is because a capacitor tends to loose charge over a period of time which needs to be refreshed again and again DRAM is used in primary storage areas and is available in various forms as EDORAM Extended Data Output RAM SDRAM Synchronous DRAM and DDR SDRAM Static RAM This type of RAM is large in physical size but is an expensive and faster memory It is faster because it is made up of flip flops to store data and these flip flops do n
90. econd line defines a new datatype named as string which is nothing but array of 30 characters Check your Progress Q1 consider the structure distance given below struct Distance int feets inches Now answer the following i what does feets and inches known as ii declare a variable of type Distance and initialize it statically iii Can we use operator between two Distance type variables If yes what does it infers iv write a function which takes two Distance variable as parameters and then returns their sum For example say D1 9 6 and D2 5 8 then D1 D2 15 feet 2 inches v Declare an array representing 10 Distances and then write a program to initialize all these 10 distances and then increase all the distances by 5 feets Consider the structure called Point as struct Point int xCoord int yCoord Write a function which accepts three Points as parameter and then checks whether the three points are collinear Consider the following structure called Element and Compound struct Element int atomic_no float atomic_mass char symbol 2 int valency struct Compound Element Elements 5 array to keep all elements present in the compound float molecular _mass Write a program to initialize a compound and show its details Summary 1 Structured data types are used in special programming situations like arrays are used when there is bulk of similar type of
91. ed into a programming language Program Testing and Debugging Program Testing means running the program executing all its instructions functions and testing the logic by entering sample data in order to check the output Debugging is the process of finding and correcting the errors in the program code Type of errors There are three types of errors generally occur during compilation and running a program They are i Syntax error ii Logical error and iii Runtime error Syntax error Every programming language has its own rules and regulations syntax If we overcome the particular language rules and regulations the syntax error will appear i e an error of language resulting from code that does not conform to the syntax of the programming language It can be recognized during compilation time Logical error Programmer makes errors while writing program that is called logical error It is an error in a program s source code that results in incorrect or unexpected result It is a type of runtime error that may simply produce the wrong output or may cause a program to crash while running The logical error might only be noticed during runtime because it is often hidden in the source code and are typically harder to find and debug Runtime error A runtime error is an error that causes abnormal termination of program during running time In general the dividend is not a constant but might be a number typed by you at runtime In th
92. ed mobile operating systems are Android and Symbian Android It is a Linux derived Mobile OS released on 5th November 2007 and by 2011 it had more than 50 of the global Smartphone market share It is Google s open and free software that includes an operating system middleware and some key applications for use on mobile devices Android applications are quiet user friendly and even one can easily customize the Smartphone with Android OS Various versions of Android OS have been released like 1 0 1 5 1 6 2 x 3 0 etc Most Android phones use the 2 x release while Android 3 0 is available only for tablets The latest Android version released is 4 2 2 The Android releases have dessert inspired codenames like Cupcake Honeycomb Ice Cream sandwich and Jelly Bean Symbian This Mobile OS by Nokia currently being maintained by Accenture designed for smartphones It offers high level of functional integration between communication and personal information management It has an integrated mail box and it completely facilitates the usage of all Google applications in your smartphone easily Symbian applications are easy to shut down as compared to Android applications Various versions like S60 series S80 series S90 series Symbian Anna etc have been released The latest Symbian releases Symbian Belle can support 48 languages Language Processors We know that computer understands instructions in machine code i e in the form of Os and 1s It is
93. ed the microprocessor It first fetches instructions tel from memory and then interprets them so as to know what is to be done If n required data is fetched from memory or input device Thereafter CPU ere executes or performs the required computation and then either stores the output or displays on the output device The CPU has three main components which are responsible for different functions Arithmetic Logic Unit ALU Control Unit CU and Memory registers Arithmetic and Logic Unit ALU The ALU as its name suggests performs mathematical calculations and takes logical decisions Arithmetic calculations include addition subtraction multiplication and division Logical decisions involve comparison of two data items to see which one is larger or smaller or equal Control Unit The Control unit coordinates and controls the data flow in and out of CPU and alsocontrols all the operations of ALU memory registers and also input output units It is also responsible for carrying out all the instructions stored in the program It decodes the fetched instruction interprets understands it and sends control signals to input output devices until the required operation is done properly by ALU and memory Memory Registers A register is a temporary unit of memory in the CPU These receive data information and then this data information is held in them as per the requirement Registers can be of different sizes 16 bit 32 bit 64 bit and so on
94. ed to embed programmer readable annotations in the source code of a computer program Those annotations are potentially significant to programmers but typically ignorable to compilers and interpreters Comments are usually added with the purpose of making the source code easy to understand Hence add comments to your code in simple English language that describes the function of the code and the reason for your decision to do it in a particular way as well Characteristics of good programming Every computer needs proper instruction set programs to perform the required assigned task The quality of the program depends upon the instructions given to it However it is required to feed provide the proper and correct instructions to the computer in order to yield provide a correct and desired output Hence a program should be developed to ensure proper functionality of the computer and also should be easy to understand A computer program should have some important characteristics which are as follows Flexibility A program should be flexible enough to handle most of the changes without having to rewrite the entire program A flexible program is used to serve many purposes For example CAD Computer Aided Design software is used for different purposes such as engineering drafting printing circuit board layout and design architectural design technical drawing industrial art etc Most of the programs are being developed for certain period and th
95. else if isupper NAME x if x 2 0 NAME x tolower NAME x 1 else NAME x cout lt lt NAME lt lt endl c How Many time the following code will be executed inti 1 i i 1 while i cout lt lt it s a while loop j d What is difference between Actual parameter and Formal parameter Give an example in C to illustrate both type of parameters e Explain different jump statements with suitable example f rewrite the following code using do while loop int i for i 0 i lt 10 i cout lt lt i i cout lt lt i g identify the error s in the following code fragment char ch int v 0 0 0 cout lt lt enter character while ch gt A amp amp ch lt Z ch gt a amp amp ch lt z switch ch case a case e case i case o case U case U v break default o cout lt lt v lt lt lt lt 0 Sample Paper IV Subject Computer Science Time 3Hours Maximum Marks 70 Note i All questions are compulsory Q No 1 a Differentiate between primary memory and secondary memory Give examples of each type of memory A The memory inside the CPU is primary memory main memory and the memory outside it is known as secondary auxiliary memory Primary Memory RAM Random Access Memory and ROM Read only Memory comes under primary memory RAM is volatile memory and ROM is non volatile me
96. enance is an important part of the life cycle of a program It is also important as far as documentation is concerned since any change pertaining to a program will require updating of internal as well as external documentation Maintenance documentation will include results of the program development steps design documents program code and test information UNIT 4 Programming in C Chapter 1 Investigation of Programming Construct in C OBJECTIVES to emphasize the programming construct available in C to investigate each and every programming construct emphasizing the situation where they can be used perfectly to demonstrate few working program in C using the constructs Why and What of Constructs in C programming 1 1 1 Flow of logic You have seen in the previous unit that a program is implementation of an algorithm steps involved in problem solving using a particular programming language like C C Java etc In our case we are using C as a high level language HLL to code our programs A programming language like C is having a bundle of programming elements like tokens identifiers variables constants operator symbols punctuation symbols etc please refer to earlier unit if you have not learnt all these terms All these programming elements helps a programmer to write simple C programs as shown below program 1 1 a simple program in C to add two integers include lt iostream h gt
97. er condition gt if lt inner condition gt some statements to be executed l on satisfaction of inner if condition statements on failure of inner if Isome statements to be executed on satisfaction of outer if condition else statements on failure of outer if Ladder if else if nested within scope of another ladder if else if if lt outer condition 1 gt if lt inner condition 1 gt Isome statements to be executed on satisfaction of inner if condition else if lt inner condition 2 gt statements on failure of inner if last statement of the inner ladder if else if some statements to be executed on satisfaction of outer if condition else if lt outer condition 2 gt statements on failure of outer if Like this you may try to keep any type if construct within the scope of other type of if construct as desired by the flow of logic of that program orkout yourself Try to nest simple if upto 4 levels ii Try to nest complex if within a compound if iii Try to nest three simple if within another simple if let us now explore few example programs using various if constructs program 2 1 program to compare three integer values to find highest out of them include lt iostream h gt void main int n1 n2 n3 O cout lt lt Input three inte
98. er is negative hence we need to calculate one s complement One s complement of 01010110 is 10101001 convert 1 into 0 and 0 into 1 Thus the 1 byte representation of number 86 is 10101001 Two s Complement method In this method the positive number is represented as the binary number If the number is negative then we need to calculate two s complement of a binary number The two s complement of a binary number is calculated by adding 1 to its one s complement Example i Represent 54 two s complement method I byte representation 54 2 27 0 27 2 13 1 13 2 6 1 6 2 3 0 3 2 1 1 1 2 0 1 The binary number is 110110 Hence the 1 byte representation is 00110110 The given number is negative hence we need to calculate two s complement One s complement of 00110110 is 11001001 convert 1 into 0 and 0 into 1 Add 1 to one s complement 11001001 1 1 2 binary equivalent 10 1 11001010 Thus 1 byte representation of number 54 is 11001010 Representing Characters A computer can handle numeric and non numeric data like letters punctuation marks and other special characters Some predefined codes are used to represent numeric and non numeric characters Some of the standards are discussed below ASCII ASCII stands for American Standard Code for Information Interchange ASCII 7 can represent 128 characters Out of 7 bits 3 are zone bits and 4 are numeric bits ASCII 8 can represent 256 characters I
99. es it back into the same string For example char myName Kamal strrev myName puts myName _ prints the reversed string as lamak 123 iv stremp char char it accepts two parameters and then compares their content alphabetically the one which comes first in the acsii chart has considered to be lower This function returns the value as integer The integer can be 0 if the two strings are equal val if the first string is bigger than the second ve if the second string is bigger than the first The above comparison is case sensitive if we want to perform case insensitive comparison then we have to take another version of the function called as strcmpi Example if strempi Kamal kamal 0 cout lt lt Not equal else cout lt lt equal 4 3 Multidimensional arrays Multidimensional arrays can be described as arrays of arrays For example a two dimensional array can be imagined as a bidimensional table made of elements all of them of a same uniform data type twoDArr represents a bidimensional array of 3 per 5 elements of type int The way to declare this array in C would be int twoDArr 3 5 and for example the way to reference the second element vertically and fourth horizontally in an expression would be twoDArr 1 3 remember that array indices always begin by zero Multidimensional arrays are not limited to two indices i e two d
100. es to model the problem being solved Eg Thermometer Speedometer Petrol pump indicator Multimeter om b Digital Computer A computer that performs calculations and logical operations with quantities represented as digits usually in the binary number system c Hybrid Computer Analog Digital A combination of computers those are capable of inputting and outputting in both digital and analog signals A hybrid computer system setup offers a cost effective method of performing complex simulations The instruments used in medical science lies in this category On the basis of Size a Super Computer The fastest type of computer Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations For example weather forecasting requires a supercomputer Other uses of supercomputers include animated graphics fluid dynamic calculations nuclear energy research and petroleum exploration PARAM Pace amp Flosolver are the supercomputer made in india b Mainframe Computer A very large and expensive computer capable of supporting hundreds or even thousands of users simultaneously In the hierarchy that starts with a simple microprocessor in watches for example at the bottom and moves to supercomputers at the top mainframes are just below supercomputers In some ways mainframes are more powerful than supercomputers because they support more simultaneous
101. ew function examples the author has forgot to write a main function a main is also a function then how the code written within the scope of the function would be executed You might be also wondering that in The general syntax of calling a function would be in above functions 3 1 3 2 and 3 4 the author has not asked the user to input values for variables used in these functions So students it done knowingly the codes within the scope of a function never gets executed if it not called from the scope of other scope Just like your badly damaged non functional land line is not going to repaired of its own until unless you are not calling a mechanic So a function has to be called from the scope of another function so that the code within the scope of the function works Usually we make this call from the scope of main function but we can call a function from the scope of any other function if the called function is defined globally The other doubt that author has not provided the input values in few function is also reasonable because a user should input the parameter values if not error will be given A user inputs the parameter values from the same scope where from it calls the function Let us know see the syntax of calling a function A function call for a non returning type function return type is void 107 function _name lt parameter list if itis defined _or leave _it_blank A function call for a non returni
102. external variable For that purpose we can use arguments passed by reference as in the function duplicate of the following example passing parameters by reference include lt iostream h gt void duplicate int amp a int amp b int amp c int main int x 1 y 3 Z 7 duplicate x y Z cout lt lt x lt lt x lt lt y lt lt y lt lt Z lt lt Z return O output x 2 y 6 z 14 The first thing that should call your attention is that in the declaration of duplicate the type of each parameter was followed by an ampersand sign amp This ampersand is what specifies that their corresponding arguments are to be passed by reference instead of by value When a variable is passed by reference we are not passing a copy of its value but we are somehow passing the variable itself to the function and any modification that we do to the local variables will have an effect in their counterpart variables passed as arguments in the call to the function void duplicate int amp a int amp b int c tp ft duplicate x yY z To explain it in another way we associate a b and c with the arguments passed on the function call x y and z and any change that we do on a within the function will affect the value of x outside it Any change that we do on b will affect y and the same with c and z That is why our program s output that shows the values stored in x y and z after the call to duplica
103. ey need updation during the course of time User Friendly A program that can be easily understood by a beginner is called user friendly It must interact with user through understandable messages In addition the proper message for the user to input data and to display the result besides making the program easily understandable and modifiable Portability Portability refers to the ability of an application to run on different platforms operating systems with or without minimal changes Since the change of platform is a common phenomenon nowadays due to the developments in hardware and the software portability has to be taken care of it In case a program is developed for a particular platform it would become obsolete after a certain period of time At the same time if a program that is developed does have the ability to work on different platforms it makes software more useable High language programs are often more portable than assembly language programs Reliability It is the ability of a program to do its intended function accurately even if there are even small changes in the computer system Moreover the program must be able to handle unexpected situation like wrong input or no input The programs which save such ability are known as reliable For example if the user does gives wrong information to input it should display a proper error message Self Documenting Code The source code which uses suitable name
104. f a String string manipulations counting vowels consonants digits special characters case conversion reversing a string reversing each word of a string Two dimensional Array Declaration initialization of a two dimensional array inputting array elements accessing array elements manipulation of array elements sum of row element column elements diagonal elements finding maximum minimum values User defined Data Types Introduction to user defined data types Structure Defining a Structure Keyword Structure declaring structure variables accessing structure elements passing structure to functions as value and reference argument parameter function returning structure array of structure passing an array of structure as an argument a parameter to a function Defining a symbol name using typedef keyword and defining a macro using define preprocessor directive Unit 1 Computer Fundamentals After studying this session students will be able to Learn the evolution of computers Learn about various generations of computer Understand the basic operation of a computer Study the functional components and their interconnections Understand the concept of booting Learn about classification of computers Introduction Computers are seen everywhere around us in all spheres of life May it be the field of education and research travel and tourism weather forecasting social networking ecommerce or any other computers have now become
105. f operators e g cout lt lt roll lt lt age lt lt endl DATATYPES IN C A datatype is just an interpretation applied to a string of bytes Data in C are of two types 1 Simple Fundamental datatypes 2 Structures Derived datatypes Simple Fundamental data types When programming we store the variables in our computer s memory but the computer has to know what kind of data we want to store in them since it is not going to occupy the same amount of memory to store a simple number than to store a single letter or a large number and they are not going to be interpreted the same way The memory in our computers is organized in bytes A byte is the minimum amount of memory that we can manage in C A byte can store a relatively small amount of data one single character or a small integer generally an integer between 0 and 255 In addition the computer can manipulate more complex data types that come from grouping several bytes such as long numbers or non integer numbers Next you have a summary of the basic fundamental data types in C as well as the range of values that can be represented with each one signed 128 to 127 char Character or small st unsigned 0 to 255 ae int signed 32768 to 32767 signed 2147483648 to Integer Abytes 2147483647 unsigned 0 to 4294967295 signed 2147483648 to Long integer Abytes 2147483647 unsigned 0 to 4294967295 float Floating point number Floating point number
106. find the Simple Interest on a given principal rate and time where the default value of the time parameter is kept 1 yr float getSimplelnt float float float 1 float getSimplelnt float p float rate float time 106 float si p rate time 100 return si The above program is having a new type of parameter known as default parameter A C function parameter can be made default if that parameter is assigned any constant either at the time of declaring it or at the time of its definition When we associate a default value to a parameter as we have associated 1 with last parameter then this value will be used if the function is getting called without passing this parameter in the call This we will again see ahead while discussing a function call The logic of the program is quite easy to understand Anyway default parameters must be always declared from right to left otherwise will cause error i e you can t make principal alone as default Following declaration is Invalid float Simplelnt float p 1000 float rate float t 1 float Simplelnt float p float rate 2 float t If you want to make principal as default parameter you have to make all the parameters on its right side default as well So the valid declaration in such case would be float Simplelnt float p 1000 float rate 2 float t 1 3 2 2 Calling a C Function from a program You might be wondering that err in the above f
107. for a b and c Ans cin gt gt a gt gt b gt gt c 3 Write the values for a and b in one line followed by value of c after two balnk lines Ans cout lt a lt lt b lt lt n n lt lt c 10 What type of errors occurs while programming Ans There are three types of errors generally occur are 1 Syntax error 2 Semantic error 3 Type error 11 How operator is different from operator Ans operator is used to find the quotient whereas operator is used to find the remainder 12 Which type of operator is used to compare the values of operands Ans Relational operators 13 How will you alter the order of evaluation of operator Ans We can use parentheses to alter the order of evaluation of an equation 14 What is the unary operator Write 2 unary operator Ans The operator which needs only one operand is called as unary operator The increment and _ _ decrement operators 15 What is output operator and input operator Ans The output operator lt lt is used to direct a value to standard output The input operator gt gt is used to read a value from standard input 16 What will be the output of following code void main int j 5 cout lt lt j lt lt j lt lt j in cascading processing starts from right to left Ans 755 17 What will be the output of following code void main int j 5 cout lt lt j j j values will be 6 6 7 From left to right
108. for the identifiers variables and methods is called self documenting code Also giving proper name for variables and methods would tell the reader of your code clearly what is it doing Hence a good program must have a self documenting code Problem solving process The problem solving process starts with the problem specifications and ends with a concrete and correct program Programming means a problem solving activity which consists of four steps They are i Understanding the problem ii Devising a plan iii Executing the plan and iv Evaluation Understanding the problem The first step is to understand the problem well It may be very difficult to understand the problem but it is crucial In general one must find out the output from the given data input data and assess the relationship between input and output data It is also important to verify whether the given information is sufficient to solve the problem or not Devising a plan It means drawing an action plan to solve the problem once understood A plan is devised from data processing to the result according to the relationship that links both of them If the problem is trivial this step will not require much thinking Executing the plan Once the plan is defined it should follow the plan of action completely and each element of the plan should be checked as it is applied In the course of execution if any part of the plan is found to be unsatisfactor
109. form Some of the prominent functions of an operating system can be broadly outlined as amp Processor Management This deals with management of the Central Processing Unit CPU The operating system takes care of the allotment of CPU time to different processes This is called scheduling Two types of scheduling techniques are employed by an operating system Priority Scheduling Each task is given CPU time according to the priority assigned to that task The program with higher priority will be given CPU time before a program with lower priority The CPU executes the task till it is completed or there is some interrupt request i e till the time operating system has to stop interrupt the current task due to an unavoidable job request The major drawback of Priority scheduling is that even a small job has to wait for a long time when a long duration job with higher priority is being executed Round Robin Scheduling This type of scheduling technique is also known as Time Sharing Scheduling In this each program or task is given a fixed amount of time to execute The CPU continues with the execution till either the allotted time is over or there is some interrupt request or the task is completed before the allotted time If the task is not completed at the end of the allotted time it is put at the end of the queue So each task gets its allotted share of CPU time This scheduling technique improves the response time and provides an interactive
110. found in a particular year s calendar For example 22 12 2012 29 02 2012 are valid dates in calendar of 2012 but 31 06 2012 or 30 02 2012 are invalid dates in calendar of 2012 Find out how many ladders of if conditions would be required to write a program for checking validity of a date Discuss your answer with your teacher 2 1 4 Nested if else You might have seen a crow s nest or any other bird s nest the materials being used to build the nest are enclosed within one another to give ample support to the nest We also have the same concept of nesting of constructs within one another to give ample strength to our program in terms of robustness flexibility and adaptability these terms you have learned in Unit 3 earlier We are now considering nesting of an if construct within another if construct i e one if is enclosed within the scope of another if The construct thus formed is called nested if Let me show you few of the syntax forms of nested if Syntaxes Simple if nested within scope of another simple if if lt outer condition gt if lt inner condition gt some statements to be executed on satisfaction of inner if condition end of scope of inner if 77 some statements to be executed on satisfaction of outer if condition end of the scope of outer if compound if nested within scope of another compound if if lt out
111. ften a looping construct executes loop for a fixed number of times based on certain looping condition placed on the looping variable or the iterator but sometimes the termination of loop is not fixed i e the termination of loop depends on some outside input These types of loops where termination of loop is not fixed and depends on outside input are called sentinels For example Consider the program given below program 2 3 program to count number of adults and minors include lt iostream h gt void main intad 0 m 0 int age 0 while age gt 0 if age gt 18 ad else m cout lt lt Input age cin gt gt age cout lt lt There are total lt lt ad lt lt adults and lt lt m lt lt minors Can you tell how many times the loop in above question runs Your answer would be probably No or better you will tell that since the termination of the loop depends upon the value of the variable age it is not fixed that how many times the loop may run Yes this is the feature a sentinel has here the value of variable age controls the execution cycle of the while loop If the value of the age inputted by the used before the start of the loop is inputted as 0 then the loop will not be executed at all because the condition fails on the start of the first cycle itself Moreover it also not fixed that after how many cycles the user may input a 0 value to stop the
112. gers Explanation Lets parse the logic of the above code shaded area to understand it using a dry run Case let us assume that the value of n1 1 n2 5 and n3 7 evaluation of the first if in the ladder if n1 gt n2 amp amp n1 gt n3 gt if 1 gt 5 amp amp 1 gt 7 gt if false amp amp true gt if false as per truth table of logical and amp amp operator since the first condition is evaluated as false so the next condition in the ladder would be evaluated if n2 gt n1 amp amp n2 gt n3 gt if 5 gt 1 amp amp 5 gt 7 gt if true amp amp true gt if true as per truth table of logical and amp amp operator since the second logic is evaluated as true it open the block of second if and the statements under the second else if block gets executed and an output is printed on the console as 5 is highest value Workout yourself 1 Try to execute the above program 2 1 using dry run method with values n1 1 n2 1 and n3 1 ii Try to implement the above program using any other type of if construct program 2 2 program to find whether a 4 digit inputted year is a leap year include lt iostream h gt void main int year 0 cout lt lt Input a 4 digit year cin gt gt year if year 4 0 if year 100 0 if year 400 0 cout lt lt Year lt lt year lt lt is a leap year
113. ght to left row no 1 represents the one s column and the second column represents ten s place The third column represents the hundred s place and so on The starting position of the top beads representing the value of five is always towards the top wall of the abacus while the lower beads representing the value of one will always be pushed towards the lower wall as a starting position Napier s Logs and Bones The idea of logarithm was developed by John Napier in 1617 He devised a set of numbering rods known as Napier s bones through which both multiplication and division could be performed These were numbered rods which could perform multiplication of any number by a number in the range of 2 9 There are 10 bones corresponding to the digits 0 9 and there is also a special eleventh bone that is used to represent the multiplier By placing bones corresponding to the multiplier on the left side and the bones corresponding to the digits of the multiplicand on the right the product of two numbers can be easily obtained Pascaline Blaise Pascal a French mathematician invented an adding machine in 1642 that was made up of gears and was used for adding numbers quickly This machine was also called Pascaline and was capable of addition and subtraction along with carry transfer capability It worked on clock work mechanism principle It consisted of various numbered toothed wheels having unique position values The addition and
114. h statement selects its branches by testing the value of same variable whereas the if else construction lets you use a series of expressions that may involve unrelated variables and complex expressions iii The if else can handle ranges whereas switch cannot c Differentiate between call by value and call by reference with help of an example A i In call by value actual arguments will be copied into the formal perameters In call by reference formal perameters are references to the actual arguments ii IN call by value if any modification is occurred to the formal perameter that change will not reflect back to the actual argument In call by reference if any modification is occurred to the formal perameter reference to the actual argument the actual argument value will be changed iii We should go for call by value when we don t want to modify the original value We should go for call by value when we want to modify the original value iv Example void Change int a int amp b a 2 a b 20 Here a is called by call by value method and b is called by call by reference So as the value of a is changed actual argument for a will not be changed as the value of b is changed actual argument for b will be changed d Write the names of the header files of the following functions i getch ii isalpha iii strepy iv sqrt A i getch conio h ii isalpha ctype h iii strepy string h iv sqrt
115. he FAT stores general information about files like filename type text or binary size starting address and access mode sequential indexed sequential direct relative The file manager of the operating system helps to create edit copy allocate memory to the files and also updates the FAT The operating system also takes care that files are opened with proper access rights to read or edit them Types of Operating System OS are classified into the following types depending on their capability of processing x Single User and Single Task OS It is used on a standalone single computer for performing a single task Operating systems for Personal Computers PC are single user OS Single user OS are simple operating system designed to manage one task at a time MS DOS is an example of single user OS Multiuser OS is used in mini computers or mainframes that allow same data and applications to be accessed by multiple users at the same time The users can also communicate with each other Linux and UNIX are examples of multiuser OS amp Multiprocessing OS have two or more processors for a single running process Processing takes place in parallel and is also called parallel processing Each processor works on different parts of the same task or on two or more different tasks Since execution takes place in parallel they are used for high speed execution and to increase the power of computer Linux UNIX and Windows 7 are examples of multiprocess
116. he loop is not having first and second part defined for it though the execution of the program remains same as version 1 since iterator has been declared and the condition for terminating the loop is implemented through a if else construct inside the loop You may observe that to terminate the loop we have used the break statement Whenever a break statement is found in a particular construct s scope it immediately comes out of the current scope Variation 3 inti O fort 3 if i lt 5 cout lt lt Hello to all i else break The above variation 3 is implemented in a similar to that of the variation 3 but it has its incrementation statement defined within if construct In all of the above variations you might have observed that it is compulsory to put a semicolon within for even when statements before and after it are absent 2 3 Nested Loops Students in section 2 1 7 we have seen that any conditional construct can be nested within any other conditional construct Similarly any looping construct can also be nested within any other looping construct and conditional constructs Let us look at the following example showing the nesting of a for loop within the scope of another for loop Inner for loop For each iteration of the outer for loop the inner for loop will iterate fully up to the last value of inner loop iterator The situation can be understood more clearly as 1 Outer Itera
117. his is the start of the compound block of main cout lt lt Study material for class XI this statement prints the sequence of string Study material for class XI into this output stream i e on monitor Every statement in the block will be terminated by a semicolon which specifies compiler the end of statement COMMENTS ina C program Comments are the line that compiler ignores to compile or execute There are two types of comments in C 1 Single line comment This type of comment deactivates only that line where comment is applied Single line comments are applied with the help of IP e g cout lt lt tomorrow is holiday the above line is proceeding with so compiler wont access this line Multi line Comment This Type of comment deactivates group of lines when applied This type of comments are applied with the help of the operators and These comment mark with and end up with This means every thing that falls between and is considered even though it is spread across many lines e g include lt iostream h gt int main cout lt lt hello world this is the program to print hello world For demonstration of comments In the above program the statements between and will be ignored by the compiler CASCADING OF OPERATOR When shift operators lt lt and gt gt are used more than one time in a single statement then it is called as cascading o
118. how students are there in one region again this information as a data ca be used to calculate that how many students are studying in KVS unary operators are the operators having one operand and two operators There are two types of unary operators i unary increment Ex a post increment a pre increment ii Unary decrement a post decrement a pre decrement ALU Arithmetic logic unit CU control unit MU memory unit System software are the software that govern the operation of computer system and make the hardware run These software can be classified into two categories Operating System amp Language Processor Booting is a process through which operating system makes the computer system ready to perform user s task g Hardware I amp III Software II amp IV Q No 2 i variable is a name given to the memory location whose value can be changed during run time ii The smallest individual unit in a program is known as a token iii Array is a combination of similar data values It is used to store more than one value under same name iv debugging is a way to correct the errors in the program during compilation v comments are non executable statements used to give the information about the code for future use vi Keywords are the reserved words programed by the programmer to perform the specific task The keyword can not be taken as a name of variable Q No 3 a While loop is entry control loop i e while loop
119. icolon This is a statement terminator Colon It indicates a labeled statement Asterisk It is used as a pointer declaration Ellipsis These are udes in the formal argument lists of unction prototype to indicate a variable number of arguments Equal to It is used as an assigning operator Pound sign This is used as preprocessor directives OPERATORS These are those lexical units that trigger some computation when applied to variables and other objects in an expression Following are some operators used in C Unary operators Those which require only one operand to trigger e g amp Binary operators these require two operands to operate upon Following are some of the Binary operators Arithmatic operators Addition me substraction A Multiplication Division Remainder Logical Operators amp amp logical AND Logical OR Relational Operator lt less than a gt Greater than lt Less than equal to gt greater than equal to equal to l not equal to Conditional operator question Assignment Operator assignment operator Assign Product Assign quotient assign Remainder amp Assign bitwise AND Assign bitwise XOR Assign bitwise OR Conditional operator The conditional operator evaluates an expression returning a value if that expression is true and a different one if the expression is evaluated as fals
120. if switch case default use of conditional operator Nested switch case break statement to be used in switch case only Loops while do while for and Nested loops Inbuilt Functions Header file Categorization Header File Function Standard input output functions stdio h gets puts Character Functions Ctype h isalnum isalpha isdigit islower isupper tolower toupper O String Function string h strucy strcat strempi strev strlen strupur strlwr strlen strcmp Mathematical Functions math h fabs pow sgrt sin cos abs Other Functions stdlib h randomize random User Defined Functions Introduction to user defined function and its requirements Defining a function function prototype Invoking calling a function passing arguments to function specifying argument data types default argument constant argument call by value call by reference returning values from a function calling functions with arrays scope rules of functions and variables local and global variables Structured Data Type Arrays Introduction to Array and its advantages One Dimensional Array Declaration initialization of One dimensional array inputting array elements accessing array elements manipulation of array elements sum of elements product of elements average of elements linear seatch finding maximum minimum value Declaration Initialization o
121. imensions They can contain as many indices as needed But be careful The amount of memory needed for an array rapidly increases with each dimension For example char alpha 100 365 24 60 60 declares an array with a char element for each second in a alpha that is more than 3 billion chars So this declaration would consume more than 3 gigabytes of memory Program 4 2 program to show use of a 2D array define WIDTH 5 define HEIGHT 3 int twoDArr HEIGHT WIDTH int n m int main for N 0 n lt HEIGHT n for m 0 m lt WIDTH m twoDArr n m n 1 m 1 return 0 We have used defined constants define macro to simplify possible future modifications of the program For example in case that we decided to enlarge the array to a height of 4 instead of 3 it could be done simply by changing the line define HEIGHT 3 to define HEIGHT 4 with no need to make any other modifications to the program Arrays as parameters At some moment we may need to pass an array to a function as a parameter In C it is not possible to pass a complete block of memory by value as a parameter to a function but we are allowed to pass its address In practice this has almost the same effect and it is a much faster and more efficient operation In order to accept arrays as parameters the only thing that we have to do when declaring the function is to specify in its parameters the element type of the array an identifier and a
122. ing OS x Time sharing Operating System It allows execution of more than one tasks or processes concurrently For this the processor time is divided amongst different tasks This division of time is 21 also called time sharing The processor switches rapidly between various processes After the stipulated time is over the CPU shifts to next task in waiting So this type of operating system employs round robin scheduling technique The system switches rapidly from one user to another but still each user feels that it is getting a dedicated CPU time Virtual Memory techniques are used in this type of operating system For example the user can listen to music on the computer while writing an article using a word processing software The user can switch between the applications and also transfer data between them Time sharing operating system can be both single user and multiuser Windows 95 and all later versions of Windows are examples of multitasking OS x Real Time Operating System It is a multitasking operating system designed for real time applications like robotics In this type of operating system the tasks have to be done within a fixed deadline System performance is good if task is finished within this deadline If it is not done the situation is called Deadline Overrun Lesser the deadline over run better is the system efficiency Hence Real Time operating systems depend not only on the logical result of the computation but also on
123. ing to write computer program is very much like learning any skill First we should understand the problems well and then try to solve it in a logical manner For example We have read many books available in the market for describing the car driving methods However we can learn driving once we actually get into the car and start driving it The same logic is applied in computer programming also Computer programming is the process of writing testing troubleshooting debugging and maintaining of a computer program An effective program is that which gives result of all different inputs including wrong input also While creating program we need to follow certain systematic approach This systematic approach comprises two steps things viz program structure and program representation The program structure is implemented by using top down or bottom up approach and is known as popular approach while the program representation plays an important role in making the program more readable and understandable What is a Good Program A Good Program means that it should produce correct and faster results taking into account all the memory constraints While making good program we need to follow certain guidelines of programming language for creating a successful program The following is the list of good programming habits that most people agree Clarity and Simplicity of Expression Expressions are used to implement a particular task It is a co
124. ion of data types bundled togeather so that all the attributes of the fruit can be captured This is true for any real world thing around you say student mobile plant etc So when we bundle many primitive data types together to define a real world thing then it is known as derived data type or structured data type or User defined data types In this chapter we would look onto two important structured data types one is Array and the other one is Structure Sometimes we need to have variables in very large quantities that too of same data type i e suppose we want 200 integer variables In this situation will you declare 200 individual variables Absolutely not This is because it will a wastage of time as well time taking task b we won t be able to manage these 200 variables in our program it will be difficult to remember the names of variable every now and then during programming So there exist special structured data type in C to tackle this situation C allows a programmer to bundle together all these same type of 200 variable under a same tag name called as Arrays So we are observing that structuring data type means bundling primitive data type in some or other way so that it solves some special programming situations 116 4 1 Arrays An array is a series of elements of the same type placed in contiguous memory locations that can be individually referenced by adding an index to a unique identifier That means th
125. is case division by zero is illogical Computers check for a division by zero error during program execution so that you can get a division by zero error message at runtime which will stop your program abnormally This type of error is called runtime error 62 Documentation The documentation includes the problem definition design documents a description of the test perform a history of the program development and its different versions and a user s manual Such a manual is designed for a naive user and illustrates the preparation of input data running the program and obtaining amp interpreting the results Program maintenance It is not directly part of the original implementation process but needs special emphasis All activities that occur after a program operation are part of the program maintenance Many large programs have long life span that often exceed the lifetime of the hardware they run on Usually the expenditure for the program maintenance will be more than the developmental cost of the program The program maintenance includes the following Finding and eliminating previously undetected program errors Modifying the current program often to improve its performance or to adapt to new laws or government regulations or to adapt to a new hardware or to a new operating system amp Adding new features or a better user interface or new capabilities to the program and amp Updating the documentation Maint
126. it on the side Divide the quotient by B REPEAT UNTIL the decimal number cannot be divided further Record the remainders in reverse order and you get the resultant binary octal hexadecimal number Example Convert the Decimal number 125 into its Octal equivalent 125 8 15 5 15 8 1 7 1 8 0 1 Answer 175 s Table to remember Decimal Binary Hexadecimal Octal 0 0 0 0 1 1 1 1 10 2 2 11 Convert from binary to octal For this conversion make the group of three digits from right to left before decimal amp left to right after decimal then assign the specific octal value Given in the table above 110101000 101010 2 gt X_e IS 13113 13113 110 101 000 101 010 2 See that in the array 110 2 corresponds to 6 110101000 101010 2 gt 650 52 8 Convert from binary to hexadecimal This conversion make the group of four digits from right to left before decimal amp left to right after decimal then assign the specific Hexadecimal value Given in the table above 110101000 101010 2 gt X 46 Pesan ic 14 141 14 0001 1010 1000 1010 1000 lo 6 ol V V V 8 A 8 110101000 2 gt 1A8 A8 46 Convert from hexadecimal to octal and binary In this conversion write the binary of specific digit For Octal three digit binary amp for Hexadecimal four digit binary Convert from octal to binary 650 52 g gt X 2 Il VV 110 101 000 101 010 650 52 g gt 110101000 101010 2 Convert from hexadecimal to
127. le Management Tools This utility helps the user in storing indexing searching and sorting files and folders on the system The most commonly used tool is the Windows Explorer and Google Desktop Application Software An application software is bought by the user to perform specific applications or tasks say for example making a document or making a presentation or handling inventory or managing the employee database An application software can be of two types General Purpose Application Software and Customized Application software General Purpose Application Software Some of the application software is made for the common users for day to day applications and uses These are also referred as Office Tools The users may use them in the manner they want Some of the popular types of general purpose application software are discussed below x Word Processor Word processor is a general purpose application software used to create documents It allows us to create edit and format documents We can use different types of fonts of various sizes underline or make bold a certain part of the text We can add clipart and other graphics into the document Popular examples of Word processing software are Writer Open Office and Microsoft Word We use word processing software for various uses like writing a simple document to designing special art effects Since we can attach images and different shapes can use different colors even a poster can be
128. list gt where return type is the value which the function returns if function does not returns any value then we may write there void function_name any valid C identifier name parameter list declaration of variables of different data types separated by comma these values are inputs passed from outside to the function The function declaration as per the syntax given above is also called as prototype declaration In C it is compulsory to declare prototype of a function before defining and using it The parameter variable in the declaration are also called Formal parameters Function Definition While function definition described about the structure of a function its inputs and output type the definition of function actually implements the code of the function While defining a function we add C code to its block as per requirement Syntax lt return type gt function name lt parameter list gt Example Declare and define a function which finds the sum of two integers and returns it int getSum int int declaration of a function int getSum inta intb definition of the function intr a b return r The above function declaration has a return type as integer because the function is meant to return a sum of two numbers Two numbers to be added are passed to the function as input parameter The parameter list is having two int separated by a comma it is not compulso
129. lue laser to read write data on a disk As the wavelength of the blue ray is shorter more data per unit area can be stored on the disk This is because due to shorter wavelength it is possible to focus the laser spot with greater precision Hence data can be packed more tightly Blue ray Disc BD was developed to enable recording rewriting and playback of high definition video HD as well as storing large amounts of data Solid State Memories The term solid state essentially means no moving parts Hence Solid state storage devices are based on electronic circuits with no moving parts no reels of tape no spinning discs no laser beams etc Solid state storage devices store data using a special type of memory called flash memory SSD Solid state drive or flash memory is used mainly in digital cameras pen drives or USB flash drives Pen Drives Pen Drives or Thumb drives or Flash drives are the recently emerged portable storage media It is an EEPROM based flash memory which can be repeatedly erased ahd written using electric signals This memory is coupled with a USB connector through which it can be plugged into the computer They have a capacity smaller than a hard disk but greater than a CD Input Output Ports and Connections Let us look at the back of a CPU Computer ports are the points where external devices or peripherals connect to a computer These ports are available at the rear or front of the computer We connect
130. mbination of Operators Operands and Constants Any expression used in the program should be understood by the user The followings are some of the points to be kept in mind while using expressions in a program 1 Use library functions to make programs more powerful Example To find output x6 Output X X X X K XK We can use output power X 6 ii Follow simplicity to maintain the clarity of expression Example X A B U VY A B X Y Then we can write X1 A B A B X2 U V Y X Y X X1 X2 iii Avoid program tricks usage whose meaning is difficult to understand by the user 58 Use of proper names for identifiers Identifiers are user defined names They are used to name things A name is associated with a function or data object constants and variables and used to refer to that function or data object Identifiers are made up of letters A Z a z digits 0 9 and the underscore character _ They however must begin with a letter or underscore and not with a digit i Give meaningful name for variable data object and function Example To calculate Area of a Square We use the variable names are Area and Side Area Side Side ii Use proper names for constants Example q 3 14 Give Pi 3 14 iii Do not use same name like custom customer or account accountant iv Do not use one letter identifiers Comments A comment is a programming language construct which is us
131. mory All the data and programs must be stored in RAM for execution But the content of RAM is not permanent Eg RAM ROM Secondary Memory Since primary memory has a limited storage capacity and is not permanent secondary storage devices are used to store large amount of data permanently There are various types of secondary devices available these days Eg Hard disks Floppy disks Magnetic Media CD ROMS DVDs Optical Media b What is the difference between semantics error and syntax error Give an example of each 3 A 1 Syntax Errors Syntax errors occur when rules of a programming language are misused Syntax refers to formal rules governing the construction of valid statements in a language Eg int a b Did not keep semicolon at the end of statement 2 Semantics Error Semantic errors occur when statements are not meaningful Semantics refers to the set of rules which give the meaning of a statement Eg X Y Z Siva plays Guitar is Syntactically and Semantically correct but Guitar plays Siva is Syntactically correct but Semantically incorrect c What do you meant by a lexical unit Give an example 2 A Token The smallest individual unit in a program is known as a token Lexical Unit There are 5 types of tokens i Keywords ii Identifiers iii Literals iv Punctuators v Operators d what is relation between Microprocessor and Microcomputer Ans Microcomputer is a computer that contain a Microprocessor e
132. mula random U L 1 L where U and L are the Upper limit and Lower limit values between which we want to find out random values For example If we want to find random numbers between 10 to 100 then we have to write code as random 100 10 1 10 generates random number between 10 to 100 Check you progress 1 Name the header files to which the following functions belongs i toupper ii fabs iii sqrt iv strcpy 2 Write a program to check whether a string variable is palidrome or not using only library function X end of chapter 3 X Summary Functions provides modularity to programs Functions can be re used Functions can be of two types User Defined and Library We have to declare and define user define functions either in program scope or header files to use them in a program To use library functions appropriate header files must be included using include directive A prototype of a function means the number data types and sequence of its parameters During function call it is very necessary to pass parameter values actual parameters to the function in the same order and type as define in its prototype The Library functions are kept within header files These header files are made as per the working nature of the function A big software must use modular approach of programming to which fu
133. n array is in fact a constant pointer pointing to a block of memory Using null terminated sequences of characters Null terminated sequences of characters are the natural way of treating strings in C so they can be used as such in many procedures In fact regular string literals have this type char and can also be used in most cases For example cin and cout support null terminated sequences as valid containers for sequences of characters so they can be used directly to extract strings of characters from cin or to insert them into cout For example program 4 6 null terminated sequences of characters include lt iostream h gt int main char question Please enter your first name char greeting Hello char yourname 80 cout lt lt question cin gt gt yourname cout lt lt greeting lt lt yourname lt lt return 0 output Please enter your first name John Hello John As you can see we have declared three arrays of char elements The first two were initialized with string literal constants while the third one was left uninitialized In any case we have to specify the size of the array in the first two question and greeting the size was implicitly defined by the length of the literal constant they were initialized to While for yourname we have explicitly specified that it has a size of 80 chars Program 4 7 program to count total number of vowels present in
134. nction is as essential programming element Sometimes instead of passing values as parameters to the function we pass its references to the function This type of calling is known as call by reference Chapter 4 Structured Data Types Arrays and Structures Objectives e to understand the meaning of structure datatypes and its availability in C To appreciate the use and importance of Arrays in C to differentiate between the use and implementation of different types of Arrays To use structures as User Defined data type to write programs To understand and use typedef Structured Data types Students till now whatever data type we have used are just primitive data types like int char float etc All these datatypes are defined within the C compiler and that is why they are also called as primitive We can define a length using int a weight using float a name using characters etc but suppose tell you please define a fruit for me in program then your mind starts wondering as you can t define a fruit just with any one datatype as you did with length weight etc A Fruit itself is a composite entity having following attributes color can be described with a name i e char taste can be described with a name i e char season can be described with int i e 1 for summer 2 for winter price can be described as float ans so on This means that to describe a fruit we need to have a collect
135. nd communicate with people Fifth Generation Computers Fifth Generation computers are still under development This generation is based on the concept of artificial intelligence In simple terms the computers of this generation are supposed to behave like humans The principles of parallel processing many processors are grouped together and 12 superconductivity are being used to develop devices that respond to human languages and will have the ability to apply previously gained knowledge to execute a task They will let them make decisions of their own to execute a task Some applications like voice recognition visual recognition are a step in this very direction ARCHITECTURE OF COMPUTER EPL lonbnal Arithmetic CAEL logic unii h pai l a e External Storie Input Devices Those devices which help to enter data into computer system Eg Keyboad Mouse Touchscreen Barcode Reader Scanner MICR OMR etc m Bar code Reader MICR used in Bank OMR Used for answer sheet evaluation Output Devices Those devices which help to display the processed information Eg Monitor Printer Plotter Projector B Printer Plotter Projector Central Processing Unit CPU Once the information is entered into the computer by the input device the processor processes it The CPU is called the brain of the computer because it is the control centre of the computer As the CPU is located on a in small chip it is also call
136. nd initial input The instructions describe a computation which will eventually produce output when executed We can use algorithm to solve any kind of problems However before writing a program we need to write the steps to solve the problem in simple English language This step by step procedure to solve the problem is called algorithm Example Let us take one simple day to day example by writing algorithm for making Maggi Noodles as a food Step 1 Start Step 2 Take pan with water Step 3 Put pan on the burner Step 4 Switch on the gas burner Step 5 Put magi and masala Step 6 Give two minutes to boil Step 7 Take off the pan Step 8 Take out the magi with the help of fork spoon Step 9 Put the maggi on the plate and serve it Step 10 Stop Further the way of execution of the program shall be categorized into three ways i sequence statements ii selection statements and iii iteration or looping statements This is also called as control structure Sequence statements In this program all the instructions are executed one after another Example Write an algorithm to find area of a rectangle Step 1 Start Step 2 Take length and breadth and store them as L and B Step 3 Multiply by L and B and store it in area Step 4 Print area Step 5 Stop In the above mentioned example all the instructions are executed one after another These examples are executed under sequential statement Selective
137. ng situations given to you find categorize each of them according to the type of flow of control they require i e Sequential Conditional or Iterative by writing S C and before them 1 Dinesh wants to find simple interest on a given amount at a particular rate of interest for fixed number of years 2 Adarsh wants to compute compound interest on a given principal rate and time but without using compound interest formula taught to him in class VIII Mahalaxmi wants to check whether her weight is an odd number or even Surekha wants to calculate area of a triangle using Heron s formula Ravi while designing a game program wants that his game character kicks his motocycle 5 times before the motorcycle gets started Ayush wants to calculate factorial of a number if the number is even otherwise he wants to find its reciprocal Mera Bank wants that its customer will be able to draw money from there account only when there is a minimum balance of Rs 1000 left in their account after the withdrawal Check and discuss your answers with your teacher Chapter 2 Using C constructs Objectives to analyze syntaxes of various programming constructs available in C to draw comparison between various programming constructs to apply the syntax of various programming constructs in problem solving 2 1 Categories of available constructs After exploring into various types of flow of control logic in different p
138. ng type function return type is some datatype return_datatype lt var_ name gt function _name lt parameter _list if_itis defined_or leave _it_blank While calling a function the value of the parameter are also called actual parameter Now let us call all the four functions which we have defined earlier i e Finction 3 1 to 3 4 Icalling of function 3 1 int isPrime int from main void main int val 0 cout lt lt input a integer to be checked cin gt gt val int r isPrime val second type of calling if r 1 cout lt lt val lt lt is prime function is returning 1 only when it found the num be a prime value else cout lt lt val lt lt is not a prime Icalling of function 3 2 void findSum int int from main void main intv1 0 v2 0 cout lt lt input two integer to be checked cin gt gt v1 gt gt v2 int s findSum v1 v2 second type of calling cout lt lt The sum is lt lt s function returns the sum which is caught by s and shown calling of function 3 3 void getHCF from main void main getHCF first type of calling II though it appears that this type of calling is an easier method but it is rarely used in actual software making industries calling of function 3 4 float getSimpleint float float float 1 from main we may call this function a different ways let us see
139. ns gets satisfied then the statements under the default case gets executed Points to remember while using a switch case construct in a program a a break statement always ends a case if break is not placed then all the cases after the current case gets executed till a break statement is met b a switch case always matches its switch variable value with a single constant case value this case value must always be a single integer value or a single character Floats and double values of switch variable are not valid i e the code below is invalid code float v 0 0 Invalid switch variable declaratio cin gt gt v switch v case 1 1 Invalid case value do something break c the cases in the switch cannot provide a range of values to be matched with the 85 switching variable i e we can t write statements like gt 4 amp amp lt 9 with cases following code is invalid char ch cin gt gt ch switch ch case gt a amp amp lt Z cout lt lt You have entered lowercase alphabet break case gt A amp amp lt Z cout lt lt You have entered uppercase alphabet break The above code gives us an example where ladder if else if has an advantage or switch case because we can have a logical statement having a range of values to be compared d The sequence of case value does not matters i e It is not compulsory to keep a lower case value as first case an
140. nted whenever num is divisible by i looping variable So on the termination of loop the variable count stores the total number of times num gets divisible in the loop We check this count value to find whether it is more than two or not if it is more than two it means num has more than two factors and hence it does not satisfies to be a prime hence we return an integer 0 to designate that it is not prime other wise we return 1 Instead of returning 1 and 0 from function you directly print using cout that num is prime or not but then don t forget to change the return type of the function isPrime to void Function 3 2 function to print all even numbers found between two given integer parameters void findSum int int void findSum int i intj int sum 0 if i lt j for int k i k lt j k if k 2 0 cout lt lt k lt lt else cout lt lt Range not valid Explanation In the above function there was no need of returning any value from its scope we have to print the even numbers found within the for loop Since a function can return only one value at a time and once its returns a value the scope of the function finishes all the variables declared in its scope dies off and are no more available to be used again So instead of returning we printed the multiple outputs using a cout Look how we have declared the function return type as void when we are not returning any value
141. ode the compiler specifies the errors at the end of compilation with line numbers The errors must be removed before the compiler can successfully recompile the source code again Interpreter The language processor that translates a single statement of source program into machine code and executes it immediately before moving on to the next line is called an Interpreter If there is an error in the statement the interpreter terminates its translating process at that statement and displays an error message Only after removal of the error the interpreter moves on to the next line for execution 23 Utilities A utility software is one which provides certain tasks that help in proper maintenance of the computer The job of utility programs is to keep the computer system running smoothly Nowadays many utility softwares are part of the operating system itself Even if there is no utility software on your computer the computer works but with the right kind of utility software loaded the computer becomes more reliable and even its processing speed increases Some of the commonly use utility softwares are antivirus Disk defragmenter backup compression etc amp Antivirus An antivirus is utility software which detects and removes computer viruses If the software is not able to remove the virus it is neutralized The antivirus keeps a watch on the functioning of the computer system If a virus is found it may alert the user flag the infected pr
142. oduce a True value i e when n becomes 41 then the iteration is ended just by terminating the scope of while construct and thereby terminating the program The Iterative flow of program is also called as Looping in above program we have used a while loop construct Let us Summarize what we have learned till now A program flow is the direction following which steps of program gets executed A program can have three types of flow of logic Sequential Flow Il refer to flowchart 1 and program 1 1 Conditional Flow refer to flowchart 2 and program 1 2 Iterative Flow l refer to flowchart 3 and program 1 3 The choice of flow of program is decided by a programmer based on the problem situation Hence you as a student must analyze the problem very well before before categorizing the problem as sequential conditional or Iterative program A programming construct in C is just a keyword which governs the flow of logic flow of control in a program and decides the various paths which a program may follow during its lifetime till it ends An if else construct governs the conditional flow of logic whereas a while construct governs the Iterative flow of logic or a loop Workout yourself Draw flowcharts for problem situation d given earlier in page no 4 and then find whether the problem follows a linear flow or conditional flow Check it out with you teacher Check your progress Here are few programmi
143. of char This will assign the value 1 to a because char is a one byte long type The value returned by sizeof is a constant so it is always determined before program execution Input Output I O In C The cout Object The cout object sends to the standard output device cout sends all out put to the screen i e monitor The syntax of cout is as follows cout lt lt data e g cout lt lt a here a can be any variable The cin operator The cin operator is used to get input from the keyboard When a program reaches the line with cin the user at the keyboard can enter values directly into variables The syntax of cin is as follows cin gt gt variablename e g cin gt gt ch here ch can be any variable e Basic structure of a C program Following is the structure of a C program tht prints a string on the screen include lt iostream h gt void main cout lt lt Study material for Class XI The program produces following output Study material for Class XI The above program includes the basic elements that every C program has Let us check it line by line include lt iostream h gt This line includes the preprocessor directive include which includes the header file iostream in the program void main this line is the start of compilation for this program Every C programs compilation starts with the main void is the keyword used when the function has no return values t
144. of b a and c cin gt gt b gt gt a gt gt Cc d b b sqrt 4 a c if d 0 cout lt lt nRoots are equal or distinct else if d gt 0 cout lt lt nRoots are Real else cout lt lt nRoots are complex ie Imaginary d1 b d 2 a d2 b d 2 a cout lt lt nD1 lt lt d1 cout lt lt nD2 lt lt d2 getch
145. ogram or kill the virus Some of the common types of viruses are Boot Sector Virus A boot sector virus displaces the boot record and copies itself to the boot sector i e where the program to boot the machine is stored So first the virus is loaded on to the main memory and then the operating system Whenever a new disk is inserted the virus copies itself to the new disk The antivirus overwrites the correct boot record on the infected boot sector and also cleans the bad sectors File Virus A file virus generally attacks executable files They can attach to various locations of the original file replace code fill in open spaces in the code or create companion files to work with an executable file Most of the file viruses are memory resident and wait in the memory until the user runs another program While another program is running the virus replicates Macro Virus This virus infects an important file called normal dot of MS Word As soon as the application is opened the virus gets activated It damages the formatting of documents and even may not allow editing or saving of documents Trojan Horse It is a code generally hidden in games or spreadsheets Since they are hidden the program seems to function as the user wants but actually it is destroying the program A Trojan horse does not require a host program to embed itself It is a complete program Its main objective is to cause harm to the data They can create bad sectors on the
146. old up to 25GB on a single layer disc and 50GB on a dual layer disc While current optical disc technologies such as DVD DVD R DVD RW and DVD RAM rely on a red laser to read and write data the new format uses a blue violet laser instead hence the name Blu ray 15 Units of Memory The smallest unit is bit which mean either O or 1 1 bit Oor1 1 Byte 8 bit 1 Nibble 4 bit 1 Kilo Byte 1024 Byte 2 Byte 1 Mega Byte 1024 KB 2 KB 1 Gega Byte 1024 MB 2 MB 1TeraByte 1024 GB 2 GB 1PetaByte 1024 TB 2 TB 1 Exa Byte 1024 PB 2 PB 1 Zetta Byte 1024 EB 2 EB 1 Yotta Byte 1024 ZB 2 ZB Booting The process of loading the system files of the operating system from the disk into the computer memory to complete the circuitry requirement of the computer system is called booting Types of Booting There are two types of booting Cold Booting If the computer is in off state and we boot the computer by pressing the power switch ON from the CPU box then it is called as cold booting Warm Booting If the computer is already ON and we restart it by pressing the RESET button from the CPU box or CTRL ALT and DEL key simultaneously from the keyboard then it is called warm booting Types of Computer On the basis of working principle a Analog Computer An analog computer is a form of computer that uses continuous physical phenomena such as electrical mechanical or hydraulic quantiti
147. on of task No body in this world Every body thinks of re usability these days in every aspect of life What will you do if your cycle wheel rim breaks down on fine day Do you will throw the whole cycle or sell the cycle as scrap No exactly not because cycles are designed in such a way that each of its parts can be repaired or replaced So you will get a new cycle rim from market and will get it fitted in your cycle This design of cycle where each of its parts have its own unique functionality and could be reassembled together to form a complete cycle is known as Modular approach of designing Each of the cycles part can thought as a Module which serves some purpose in the whole cycle but is very essential for proper functioning of the cycle The whole concept is nothing but based on Divide and Rule philosophy A bigger system is divided into smaller components so that each of these smaller parts could handled easily and effectively These smaller parts when integrated gives rise to the bigger system Just think GOD has also created human beings as a modular entity We humans have a body which is integration of organ system and each of these organ system is again integration of some organs So here organs are acting as modules These modules organs could be taken care of individually when we often fall ill Can you rightly describe what is opposite word for modularity Any system which is not modular is known as monolithic 3173 or indivisi
148. orld there exist some programming situation which needs branched flow of program instructions or in simple terms we may say that the program demands several paths of execution Thus A program having multiple paths of execution where each path leads to different type of completion states are categorized as Conditional Programs The selection of paths of execution depends upon a logical decision being made look at the rhombuses When we consider our problem then it is seen that a number when it is satisfying both the logical conditions at two rhombuses ends up with a result that it is divisible by both values 3 and 5 execution path 1 whereas if it not satisfying either of the two logical conditions placed at two rhombuses then the program ends up with another result showing it is not divisible by both of them together Satisfying any one of the logical condition would not solve our purpose as we are expecting a logical AND amp amp Now let us convert the above flowchart 2 in a C program You may not understand all the parts of programs here so don t worry it will be described in the later part of the chapter Program 1 2 program to implement the problem described by flowchart 2 include lt iostream h gt void main intnum 0 declaring a variable num cout lt lt Input the number you want to check cin gt gt num Inputting value of n if n 3 0 checking whether n is divisible by 3 con
149. ors instead of success 3 Run Time error An abnormal program termination during execution is known as Run time Error e g If we are writing a statement X A B C the above statement is grammatically correct and also produces correct result But what happen if we gave value 0 to the variable c this statement will attempt a division by 0 which will result in illegal program termination Error will not be found until the program will be executed because of that it is termed as run time error 3 Logical Error A logical error is simply an incorrect translation of either the problem statement or the algorithm e g root1 b sqrt b b 4 a c 2 a the above statement is syntactically correct but will not produce the correct answer because the division have a higher priority than the addition so in the above statement division is performed first then addition is performed but in actual practice to do addition performed then divide the resultant value by 2 a Manipulators Manipulators are the operators used with the insertion operator lt lt to modify or manipulate the way data is displayed There are two types of manipulators endl and setw 1 The endl manipulator The endl manipulator outputs new line It takes the compiler to end the line of display cout lt lt Kendriya Vidyalaya Sangathan lt lt endl cout lt lt Human Resource and Development The output of the above code will be Kendriya Vidyalay
150. ot require any refreshing Static RAM is also volatile and is easier to use as compared to dynamic RAM These are used in specialized applications Read only memory ROM As the name suggests a ROM is a type of memory that can perform read operation only The contents of ROM are written by the manufacturer and come along with the computer We cannot change its contents or write something else on it Data is written on to the ROM at the time of its manufacture and it cannot be changed thereafter It is a non volatile memory which means that contents stored in it are not lost even when the power to the computer is switched off ROMs are used in applications where the information once written need not be altered They hold certain essential instructions such as interrupt service routines or a monitor program controlling the machine Instructions that are needed to start the computer are also stored in the ROM ROMs are slower as compared to RAMs and are available in various types x Programmable Read Only Memory PROM This type of ROM can be programmed even after its manufacture using a PROM programmer circuit But once a PROM is programmed it becomes just like ROM i e it cannot be changed x Erasable Programmable Read Only Memory EPROM In this type of ROM the contents can be erased and the memory can be reprogrammed To erase the data an EPROM is exposed to 36 ultraviolet light and then it can be reprogrammed using a PROM
151. pair of void brackets For example the following function void procedure int arg accepts a parameter of type array of int called arg In order to pass to this function an array declared as int myarray 40 it would be enough to write a call like this procedure myarray 4 2 Structures In C 4 2 1 Why Structures To understand the basic need let us proceed with a sample programming scenario Problem Definition Mr Chamanlal is Human resource manager in a construction company He has different responsibilities related to manpower and its utilities One of his main duties is to keep the record of data related to the Workers who are working in the construction company 125 The information which is to be kept regarding a Worker are gt Name gt Sex Data members gt Age gt Rate per day Chamanlal wants to write a C program which can keep track of the information related to all Workers working in the construction company Solution The above problem could be solved in C using 3 ways They are gt Using Simple variables to store all information of each employees gt Using Arrays to store related information of each employees gt Using C Structures Let us explore all these three techniques to store information of each Worker of the company Assuming that there are total 20 Workers Using Variables As we have learned in class XI that any type of data could be stored in a C variable having
152. pper and lower case letters differently The first character must be a letter the underscore counts as a letter Pen time580 s2e2r3 _dos _HJI3_ JK LITERALS The data items which never change their value throughout the program run There are several kind of literals e Integer constant e Character constant e Floating constant e String constant Integer constant Integer constant are whole numbers without any fractional part An integer constant must have at least one digit and must not contain any decimal point It may contain either or _ A number with no sign is assumed as positive e g 15 1300 58795 Character Constant A character constant is single character which is enclosed within single quotation marks e g A Floating constant Numbers which are having the fractional part are referred as floating numbers or real constants it may be a positive or negative number A number with no sign is assumed to be a positive number e g 2 0 17 5 0 00256 String Literals It is a sequence of letters surrounded by double quotes E g abc PUNCTUATORS The following characters are used as punctuators which are also know as separators in PL 4 E OO S C Puntuator Name Function Brackets These indicates single and multidimensional array subscripts Parenthesis These indicate function calls and function parameters Braces Indicate the start and end of compound statements Sem
153. programs But supercomputers can execute a single program faster than a mainframe c Mini Computer A midsized computer In size and power minicomputers lie between workstations and mainframes In the past decade the distinction between large minicomputers and small mainframes has blurred however as has the distinction between small minicomputers and workstations But in general a minicomputer is a multiprocessing system capable of supporting from 4 to about 200 users simultaneously Generally servers are comes in this category d Micro Computer i Desktop Computer a personal or micro mini computer sufficient to fit on a desk ii Laptop Computer a portable computer complete with an integrated screen and keyboard It is generally smaller in size than a desktop computer and larger than a notebook computer iii Palmtop Computer Digital Diary Notebook PDAs a hand sized computer Palmtops have no keyboard but the screen serves both as an input and output device e Workstations A terminal or desktop computer in a network In this context workstation is just a generic term for a user s machine client machine in contrast to a server or mainframe Software Concepts After studying this chapter the student will be able to Learn different types of Software System Software Operating system Language Processors Utility Software Antivirus Compression tools Backup Disk Defragmentor Application Software General
154. re include Microsoft Internet Explorer which comes bundled up with any Microsoft operating system The author of the freeware software is the owner of the software though people may use it for free The source code is not available so no modifications can be done Freeware should not be mistaken with Open Source Software or Free Software x Open source Open Source Software OSS is the software which gives the users freedom to run use the software for any purpose and in any manner They can be used modified and even redistributed In simple terms it can be freely used but it may not be free of charge The source code is freely available to the customer Python Tux Paint etc are examples of Open Source Software x Free Software This type of software is freely accessible and can be freely used modified copied or distributed by anyone And no licence fee or any other form of payment need to be made for a free software The source code is also accessible in case of free softwares Data Representation in Computers After studying this chapter the student will be able to Learn about binary octal decimal and hexadecimal number systems Learn conversions between two different number systems Understand internal storage encoding of characters ASCII ISCII and UNICODE Binary Representation of Data In order to work with data the data must be represented inside the computer Digital computers represent data by means of an easily iden
155. re usability 102 How Functions in C are related to program modules Just as a software is divided into modules each modules into sub modules a sub module is further divided into several functions So we may call a function as a micro level module of a bigger software A function in C is smaller section of code of bigger module program is re usable piece of code is very specific in nature as it performs a specific task is often called many times in a program Thus a C function have all the advantages which a module has in a software 3 2 Types of function Functions in C are of two basic types a User Defined written by a programmer as per his her requirement domain b Library Function already available with C compiler and stored as Library from where they can be called and used in any C program 3 2 1 User Defined Functions A user define function in C is always created by programmer according to his her program requirements Suppose if some programmer is making software for school management then his list of user defined functions may have functions such as getFee calcResult setExam all these functions will be used only in school management software not any where else as they are specially tailored function for school management software Let us see the syntax to declare a user defined function Function Declaration lt return type gt function name lt parameter
156. rite a program which inputs day dd month mm and year yyyy and checks whether it is a valid date or not A valid date must lie on the calendar Dipu Jwellers gives discount on a fixed purchase total based on following criteria Offer Offer Months Discount Purchase total Winter Bonanza Oct to Feb 30 Between 3000 to 5000 Summer Bonanza Mar to June 20 Between 10000 to 12000 Monsoon Bonanza July to Sep 10 Between 2000 to 10000 If the purchase amount of a customer does not lies between the given purchase total then no discount should be given Write a program to calculate the Bill amount of a purchase after giving proper discount 2 1 5 switch case statement switch case construct is a type of conditional construct which resembles the same flow of logic as that of ladder if else if with few exceptions Let us observe the syntax of the switch case construct of C Syntax switch lt switching variable switch expression gt case lt value 1 gt do something if switching variable value matches with that of value 1 break case lt value 2 gt do something if switching variable value matches with that of value 2 break case lt value 3 gt do something if switching variable value matches with that of value 3 break case lt value n gt do something if switching variable value matches with that of value n break default Ido something if switching
157. rogram that is loaded onto its memory A user cannot communicate directly with the computer hardware so the operating system acts as an interface between the user and the computer hardware Some of the popular operating systems used in personal computers are DOS Windows Unix Linux Solaris etc An operating system can be a Single User or a Multiuser operating system A single user operating system allows only one user to work at any time but a multiuser operating system allows two or more users to use a powerful computer at the same time For example Windows 7 is a single user operating system while Linux is a multiuser operating system Need for an Operating System Operating system provides a platform on top of which other programs called application programs can run As discussed before it acts as an interface between the computer and the user It is designed in such a manner that it operates controls and executes various applications on the computer It also allows the computer to manage its own resources such as memory monitor keyboard printer etc 19 Our choice of operating system therefore depends to a great extent on the CPU and the other attached devices and the applications we want to run The operating system controls the various system hardware and software resources and allocates them to the users or programs as per their requirement Functions of an Operating System An operating system has variety of functions to per
158. rogramming situations let us go through the detailed syntax format of each of the programming constructs available in C using which we can monitor flow of control in our program Here is one diagram which categorizes C constructs in detail Programming Constructs Simple programs if Simple if for loop Entry control using identifiers operators expressions if else Compound if while loop Exit control etc if else if complex if Ladder do while Exit control does not requires if else branching or repetition Nested if of statements switch case statement Conditional Operator Let us deal each one of them one after another in detail 2 1 Conditional Constructs 2 1 1 Simple If syntax if lt conditional expression logical statement gt I statements to be executed when logical statement is satisfied i e when the logical statement yields a true value points to remember i a logical statement always evaluates as true false ii any value in C other than zero positive negative is considered to be true whereas a zero 0 is considered to be false iii lt gt in syntax is known as a place holder do not type it while writing program It only signifies that any thing being kept there varies from program to program iv if there exists only one line of program statement under if scope then we may ommit
159. ry to write a variable names of the parameters in declaration A semicolon is terminating the declaration of function The definition of function is having code written within its scope where the sum is calculated over the passed parameters a and b and the result is returned using a keyword return It is compulsory that the return data type must be same as that of the datatype of the variable returned using return statement Workout yourself Declare the prototype of a function which i multiplies three integers and return the product ii checks whether a passed integer parameter is even or odd iii prints your name 20 times Consider the few more definition of functions related to various program Function 3 7 function to check whether a given number is prime or not int isPrime int int isPrime int num int count 0 for inti 1 i lt num i if num 0 count if count gt 2 return O II more than two factors means it is not prime hence a false value is returned else return 1 II exactly two factors i e 1 and num itself means num is prime hence return a II true value i e 1 In the above function if the passed parameter to the function i e num would be a prime it will have exactly two factors counted out in variable count and if not would have more than 2 factors After we conduct a looping over the num to check its divisibility by every value from 1 to num we get count increme
160. s Since instructions are simple RISC processors are relatively simple to design Examples of RISC processor is SPARC POWER PC etc CISC It stands for Complex Instruction Set Computer A CISC chip such as Intel Pentium provides programmers with hundreds of instructions of variable sizes and the processing circuitry includes many special purpose circuits that carry out these instructions at high speeds These instructions interface with memory in multiple mechanisms with complex addressing modes In this case the program size is reduced and hence lesser number of memory cycles are required to execute the instruction So fewer general purpose registers 8 12 are present in CISC processors Also less number of memory cycles result in faster execution of the program x EPIC It stands for Explicitly Parallel Instruction Computing It is a computer architecture that combines the best feature of both RISC and CISC It does not use instructions of any fixed length but rather aims at parallel processing of instructions It uses a bundle of complex instructions that in addition to basic instruction also contain information on how to run the instruction in parallel with other instructions This greatly increases the efficiency of an EPIC processor I A 64 Intel Architecture 64 is Intel s first 64 bit processor based on EPIC Memory Concepts Memory is one of the most important components of a computer system as it stores data and instructions Every
161. s commonly main itself During compilation if the compiler could not find the definition for a particular function it would just assume that the function was defined in another file If this isn t the case there s no way the compiler would know it doesn t look at the contents of more than one file at a time The linker on the other hand may look at multiple files and try to find references for the functions that weren t mentioned ERRORS There are many types of error that are encountered during the program run following are some of them 1 Compiler error The errors encountered during the compilation process are called Compiler error Compiler error are of two types Syntax error Semantic error Syntax Error Syntax error is the one which appears when we commit any grammatical mistakes These are the common error and can be easily corrected These are produced when we translate the source code from high level language to machine language e g cot lt lt endl This line will produce a syntax error as there is a grammatical mistake in the word cout Semantic error These errors appear when the statement written has no meaning e g atb c this will result a semantically error as an expression should come on the right hand side of and assignment statement 2 Linker Errors Errors appear during linking process e g if the word main written as mian The program will compile correctly but when link it the linking window will display err
162. sh zero Our array of 20 elements of type char called myStr can be represented storing the characters sequence Merry Christmas as myStr M e r r y C h o 0 1 2 3 4 Notice how after the valid content a null character 0 has been included in order to indicate the end of the sequence The panels in gray color represent char elements with undetermined values Initialization of null terminated character sequences Because arrays of characters are ordinary arrays they follow all their same rules For example if we want to initialize an array of characters with some predetermined sequence of characters we can do it just like any other array char myword H e 1 T o 0 In this case we would have declared an array of 6 elements of type char initialized with the characters that form the word Hello plus a null character 0 at the end 121 But arrays of char elements have an additional method to initialize their values using string literals In the expressions we have used in some examples in previous chapters constants that represent entire strings of characters have already showed up several times These are specified enclosing the text to become a string literal between double quotes For example the result is is a constant string literal that we have probably used already Double quoted strings are literal constants whose t
163. sh cycles to prevent its contents being lost 14 However DRAM uses only one transistor and a capacitor per bit allowing it to reach much higher densities and with more bits on a memory chip be much cheaper per bit SRAM is not worthwhile for desktop system memory where DRAM dominates but is used for their cache memories Non Volatile Memory ROM Non volatile memory is computer memory that can retain the stored information even when not powered gt amp Examples of non volatile memory are flash memory and ROM PROM EPROM EEPROM memory used for firmware such as boot programs Cache Memory Cache memory is random access memory RAM that a computer microprocessor can access more quickly than it can access regular RAM As the microprocessor processes data it looks first in the cache memory and if it finds the data there from a previous reading of data it does not have to do the more time consuming reading of data from larger memory It is of two types L1 cache is on the same chip as the microprocessor L2 is usually a separate static RAM SRAM chip Secondary Memory A Hard Disk Local Disk B Optical Disks CD R CD RW DVD R DVD RW C Pen Drive D Floppy Disks F Memory Cards G External Hard Disk H Blu Ray Disk Blu Ray Disk Blu ray not Blue ray also known as Blu ray Disc BD is the name of a new optical disc format The format offers more than five times the storage capacity of traditional DVDs and can h
164. sider the first rhombus of the flowchart 2 if n 5 0 checking whether n is divisible by 5 consider the second rhombus II of flowchart 2 cout lt lt The number you inputted is divisible by both 3 and 5 path1 else cout lt lt The number you inputted is not divisible both by 3 and 5 path2 else cout lt lt The number you inputted is not divisible both by 3 and 5 path2 The shaded part of the above program shows how a conditional branching is implemented with an if else construct of C Workout yourself Draw flowcharts for problem situation b given earlier in page no 4 and then find whether the problem follows a linear flow or conditional flow Check it out with you teacher 1 1 3 Iterative Flow Cyclic Flow Now let us solve the problem situation c given in page 4 with the help of a flowchart i e A teacher wants to calculate the average marks for each of his 40 pupils in a class Let us assume that the teacher maintains count of his her students in a variable say n Let the teacher starts n from 1 student i e n 1 Let there are marks in five subjects say s1 s2 s3 s4 and s5 and Avg as Average We must remember that this problem demands calculation of average marks of each student i e Average marks for each of the individual 40 students would be calculated and displayed 68 C sat gt Flowchart 3 Observe the above flowchart 3 and compare it with flow
165. study material is For the academic year 2012 13 the task of preparing the study material has been entrusted with Kendriya Vidyalaya Sangathan BhubaneswarRegion for the students of Class XI in Computer Science Every effort has been made by four of your chosen PGTs Computer Science to present the material in brief but not compromising on the matter to the presented Stress has equally been laid on the HOTs Higher Older Thinking Skills questions as well as the simpler concepts All the four PGTs Computer Science Sh Arun Kumar Sh Kamal Kant Gupta Sh Anil Kumar S S Sh Munendra Prakash deserve the appreciation for their efforts I am sure the support material will definitely of help to our students to prepare for the examinations besides helping them in understanding the subject R KALAVATHD DEPUTY COMMISSIONER KVS BHUBANESWAR REGION REVIEW REPORT I have the privilege in reviewing the support study material for Computer Science 083 for class XI session 2013 14 and I am really thankful to our Esteemed Deputy Commissioner KVS RO Mumbai Ms L CHARI for entrusting me this responsibility The study support material of Computer Science 083 for class XI has been thoroughly reviewed in accordance with the curriculum and marking scheme of CBSE Further Unit I Computer Fundamental and Unit II Programming Methodology have been modified as per CBSE norms as these two units are having maximum theoretical portion
166. switch case construct int ch cin gt gt ch If ch 1 cout lt lt Laptop else If ch 2 cout lt lt Desktop else if ch 3 cout lt lt Notebook else cout lt lt Invalid Choice c Convert the following code segment into do while loop include lt iostream h gt void main inti for i 1 i lt 20 i cout lt lt n lt lt i d Given the following code fragment int ch 5 cout lt lt ch lt lt n lt lt ch lt lt n i What output does the above code fragment produce ii What is the effect of replacing ch with ch 1 6 a Which header files are required for the following i frexp ii sqrt iii rand iv isupper b Evaluate i 12 10 X 2 ii 347 s X 10 iv 100 10 X z2 7 a Write a C program to check a year for leap year or not b Write a C program to check a number for Armstrong or not c Write a C program to calculate the factorial of any given number d Write a C program to print the Fibonacci series e Write a C program to print table a given number Answer key Q No 1 a Major OS functions are listed below 1 Process Management 2 Storage Management 3 Information Management Student has to describe all in brief The processed information can be used as a data again to produce a next level information For example totoal no of students school wise can give the information that
167. syllabus UNIT 1 COMPUTER FUNDAMENTALS 18 Theory 6 Practical Periods Evolution of computers Basics of computer and its operation Functional Components and their interconnections concept of Booting Classification of Computers Software concepts Types of Software System Software Utility Software and Application Software System Software Operating System Complier Interpreter and Assembler Operating System Need for Operating System Functions of Operating System Processor Management Memory Management File Management and Device Management Types of Operating System interactive GUI based Time Sharing Real Time and Distributed Commonly used operating system UNIX LINUX Windows Solaris BOSS Bharat Operating System Solutions Mobile OS Android Symbian Utility Software Anti Virus File Management tools Compression tools and Disk Management tools Disk Cleanup Disk Defragmenter Backup Open Source Concepts Open Source Software Freeware Shareware Proprietary Software Application Software Office Tools Word Processor Presentation Tool Spreadsheet Package Database Management System Domain Specific tools School Management System Inventory Management System Payroll System Financial Accounting Hotel Management Reservation System and Weather Forecasting System Number System Binary Octal Decimal Hexadecimal and conversion between two different number systems Internal Storage encoding of Characters ASCII
168. t lt endl result A1 cout lt lt A1 lt lt B2 lt lt endl result B2 cout lt lt A1 lt lt B2 lt lt endl D Find the output include lt iostream h gt void main int i 0 x 0 do if i 5 0 cout lt lt x x j while i lt 10 cout lt lt n lt lt x e Find the correct possible output void main randomize char city 10 del chn kol bom bng int fly for int i 0 i lt 3 i fly random 2 1 cout lt lt city fly lt lt Output 1 Del chn kol 2 Chn kol chn 3 Kol bom bng 4 Kol chn kol Q No 3 a what do you mean by literals What are the different kind of literals b Explain the types of errors in c c what is the difference between structure and arrays d what do you mean by dynamic and static allocation e what is the difference between a and a in c f What do you mean by code generation Q No 4 a What do you mean by nested structure Explain with suitable example b What is data abstraction Explain the concept with the help of an example c Convert the following equations to C statements i s 14 1 x 1 x2 1 x3 A s 1 1 x 1 x x 1 x x x ii V 4 3Nr3 A V 4 3 3 1415 r r r d Explain any two string handling functions with syntax and examples 157 e i AC 20 16 2 s ii 4A56 16 10 s f Find the 1 s and 2 s complement of 128 g explain
169. t is an extended form of ASCII 7 ISCII Indian Standard Code for Information Interchange A lot of efforts have gone into facilitating the use of Indian languages on computers In 1991 the Bureau of Indian Standards adopted the ISCII It is an 8 bit code which allows English and Indian Scripts alphabets to be used simultaneously Characters coded in ISCII need 8 bits for each character Unicode Unicode is a new universal coding standard adopted by all new platforms It is promoted by Unicode Consortium which is a non profit organization Unicode provides a unique number for every character irrespective of the platform program and the language It is a character coding system designed to support the worldwide interchange processing and display of the written texts of the diverse languages Microprocessors and Memory Concepts After studying this session students will be able to Learn about a microprocessor and its characteristics Classify the microprocessors RISC CISC and EPIC Learn the various units of memory Understand the memory types Primary memory and Secondary memory Learn about various input output ports connections Microprocessor We studied that the Central processing unit processes data inside the computer It interprets all the instructions given to it and carries out these instructions A microprocessor is a Central Processing Unit CPU on a single chip It is a multipurpose programmable device cons
170. tails you must write down a list of specifications Specifications are precise definitions of what the program must do It must include the following at least x Input what data must be included as input and in which form Output what data must the program produce and in which form in order to solve the problem Note At the end of the problem definition step you should have a list of specifications Problem Analysis In this step the problem has to be fragmented into smaller and manageable parts The original problem has to be analyzed and divided into a number of sub problems as these sub problems are easier to solve and their solutions would become the components of the final program Each sub problem is divided into further smaller ones and this fragmentation has to be continued to achieve simple solutions The use of modular programming is to get proper solution Modular Programming Modular Programming is the act of designing and writing programs as functions a large program is divided into the small individual components that each one performs a single well defined function which has minimal interaction between the sub programs It means that 61 the content of each function is cohesive and there is low coupling between them There are two methods available for modular programming They are top down design and bottom up design Top Down design The principles of top down design dictate that a program should be divided into a m
171. te shows the values of all the three variables of main doubled If when declaring the following function void duplicate int amp a int amp b int amp c we had declared it this way void duplicate int a int b int c i e without the ampersand signs amp we would have not passed the variables by reference but a copy of their values instead and therefore the output on screen of our program would have been the values of x y and z without having been modified Passing by reference is also an effective way to allow a function to return more than one value For example here is a function that returns the previous and next numbers of the first parameter passed more than one returning value include lt iostream h gt void prevnext int x int amp prev int amp next prev x 1 next x 1 int main int x 100 y Z prevnext x y Z cout lt lt Previous lt lt y lt lt Next lt lt z return 0 Ouput Previous 99 Next 101 3 2 4 Arguments passed as const parameter Look at the following protoype void myFunction const int x 10 The above function is declaring its first parameter as const i e even if the user tries to pass value to this argument the new value will not change the value assigned to the const parameter even in the scope of the function also it will remain unchaged Let us see one example void myFunction const int x 10 main
172. the outer expression here a contains 3 B contains 4 In Example 1 B is increased before its value is copied to A While in Example 2 the value of B is copied to A and then B is increased Practice Session 1 What is the name of the function that should be present in all c program Ans main 2 What are C comments Ans comments are internal documentation of a program which helps the program for many purposes 3 What is indentation of a program Ans It is the systematic way of writing the program which makes it very clear and readable 4 What is include directives Ans it instructs the compiler to include the contents of the file enclosed within the brackets into the source file 5 What is role of main in c program Ans This is the first line that a C compiler executes Program starts and end in this function 6 What is a header file Ans Header file provide the declaration and prototypes for various token in a program 7 What is the purpose of comments and indentation Ans the Main purpose of comments and indentation is to make program more readable and understandable 8 What are console input output functions Ans Console I O functions are cout and cin 9 Write an appropriate statement for each of the following 1 Write the values for a amp b in one unseperated by blanks and value of after two blanks lines Ans cout lt lt a lt lt b lt lt endl lt lt endl lt lt c 2 Read the values
173. the output would be 23 next prime to 20 You might be knowing DNA in Biology it is a genetic molecule made of four basic types of nucleotides The four nucleotides are given one letter abbreviations as shorthand for the four bases Ais for adenine G is for guanine C is for cytosine T is for thymine When considering the structure of DNA it is made of two strands Each of these strands are made of long chains of above nucleotides like AAGCTCAGAGCTATG 1st strand TTCGAGTCTCGATAC 2 strand Each of the nucleotide of 1 strand pairs with nucleotide in other strand using bond These bonding obeys the following rule 1 A will always pair with T and vice versa II G will always pair with C and vice versa as it can be observed in the two strands given above Write a program in C which allows user to input the nucleotide character sequence of 1 strand and print the probable sequence of the other strand The user must provided opportunity to input a strand of any size and only stops when user inputs an out of order character instead of A G C amp T Chapter 3 Functions in C Objectives to analyze how modularity is implemented in a program at its lowest level To appreciate the use and importance of function in C to program different types of functions and implement them practically To understand difference between User Define Function and Library function 3 1 Why to use functions Who likes unnecessary repetiti
174. the time in which the results are produced amp Distributed Operating System On a network data is stored and processed on multiple locations The Distributed Operating System is used on networks as it allows shared data files to be accessed from any machine on the network in a transparent manner We can insert and remove the data and can even access all the input and output devices The users feel as if all data is available on their workstation itself amp Interactive Operating System This is the operating system that provides a Graphic User Interface GUI through which the user can easily navigate and interact The computer responds almost immediately after an instruction has been entered and the user can enter new instructions after seeing the results of the previous instructions Commonly Used Operating Systems Some of the commonly used operating systems are discussed below 1 Windows Microsoft launched Windows 1 0 operating system in 1985 and since then Windows has ruled the world s software market It is a GUI Graphic User Interface and various versions of Windows have been launched like Windows 95 Windows 98 Win NT Windows XP Windows 7 and the latest being Windows 8 2 Linux Linux is a free and open software which means it is freely available for use and since its source code is also available so anybody can use it modify it and redistribute it It can be downloaded from www linux org It is a very popular operating system
175. tified symbol called a digit Numbering Systems Each number system has a base also called a Radix A decimal number system is a system of base 10 binary is a system of base 2 octal is a system of base 8 and hexadecimal is a system of base 16 What are these varying bases The answer lies in what happens when we count up to the maximum number that the numbering system allows In base 10 we can count from 0 to 9 that is 10 digits Number System Base Symbols used Binary 2 0 1 Octal 8 0 1 2 3 4 5 6 7 Decimal 10 0 1 2 3 4 5 6 7 8 9 Hexadecimal 16 0 1 2 3 4 5 6 7 8 9 A B C D E F where A 10 B 11 C 12 D 13 E 14 F 15 Converting a number from one Base to another Other Binary Octal Hexadecimal to Decimal Method to convert other to Decimal 1 Start at the rightmost bit 2 Take that bit and multiply by B where B is the base of other number system and n is the current position beginning at 0 and increasing by 1 each time 3 Sum each terms of product until all bits have been used Example Convert the Binary number 101011 to its Decimal equivalent 1 2 0 244 1 27 0 27 1 2 1 2 32 0 8 0 2 1 43 10 Convert the Octal number 321 to its Decimal equivalent IKR 2 8 1 8 192 16 1 209 10 Decimal to Other Binary Octal Hexadecimal Method to convert a Decimal number into its Binary equivalent 28 Divide the decimal number by B Take the remainder and record
176. tion i 1 1 Inner Iteration j 1 output 2 Inner Iteration j 2 output 3 Inner Iteration j 3 output 2 Outer Iteration i 2 1 Inner Iteration j 1 output 2 Inner Iteration j 2 output 37 Inner Iteration j 3 output You can observe that j is iterated from 1 to 2 every time i is iterated once Workout Yourself print a multiplication table from 1 to 10 using concept of nested for loop Let us summarize what we have learned till now i There are two basic types of Conditional constructs if construct and switch case statement The if has four different types of variations simple compound complex and nested ii There are three basic types of Iterative Constructs while do while and for Out of these while and for have similar flow of execution whereas do while is bit different iii for and while are called as Entry Control Loop whereas do while is called as exit control loop Check your progress 1 Write C program to sum of following series 1 1 1 1 1 S 1 nterms 2 By 4 De 6 Wo E ii S 1 ee ge es ii S 1 2 3 5 6 7 nterms 1 3 n SSS Gay C e Using while loop find the sum of digits of number if the inputted number is prime if number is 99 then print the nearest prime number For example if user inputs number 17 then the output would be 1 7 8 if user inputs number 20 then
177. torage media information is stored and read using a laser beam The data is stored as a spiral pattern of pits and ridges denoting binary 0 and binary 1 Examples of optical media are CDs DVDs etc Compact Disk A compact disk or CD can store approximately 650 to 700 megabytes MB of data We must have a CD drive in our computer to read them The bits 0 and 1 are encoded as transitions between raised ridges and etched pits which are lined up in a spiral like pattern This pattern is then stamped into a 1 2 mm clear polycarbonate disc a CD which ils then covered with a super thin coating of reflective metal usually aluminum or gold and a label To read the data an infrared laser is beamed through the CD s polycarbonate substrate The wavelength of light that bounces off the muirror like reflective backing is then measured A pit scatters the light and the ridge reflects the light Since pits and ridges pass different amounts of light the fluctuations in the reflected beam are then translated back into the original ones and zeros There are three types of CDs CD ROM It stands for Compact Disk Read Only Memory and data is written on these disks at the time of manufacture Thereafter this data cannot be changed but can only be read by a laser beam in the form of a continuous spiral CD ROMs are used for text audio and video distribution like games encyclopedias and application softwares CD R It stands for Compact Disk
178. tructed using Metal Oxide Semiconductor MOS technology In 1971 Intel Corporation fabricated the first microprocessor 4004 It could do only add and subtract operations and that too it could process only 4 bits at a time But Intel 4004 powered one of the first portable electronic calculators and since then the microprocessor technology has come a long way Today we have processors with which can process upto 128 bits at a time at the speed of billion instructions per second Let us now have a look at the characteristics of microprocessors x Instruction Set It is the set of instructions that the microprocessor executes Word Length The number of bits processed in a single instruction is called word length or word size The word size is directly proportional to the processing power of the CPU During the processing the internal general purpose registers hold data So if internal registers can hold data upto 8 bits the word length is 8 bits If it can process 16 bits at a time then the internal registers can hold upto 16 bits at a time and so on Hence a 32 bit processor is about 4 times faster than an 8 bit processor Examples of word lengths are 16 bit 32 bit 64 bit The terms 16 bit CPU 32 bit CPU 64 bit CPU are used very often while talking about CPUs Now we know that these terms mean the maximum number of bits a given CPU can handle at a time x System Clock Speed The microprocessor s pace is controlled by the System Clock The
179. try is determined by the development in technology Each phase generation of computer development is characterized by one or more hardware software developments that distinctly improved the performance of the computers of that generation Based on various stages of development computers can be divided into different generations The First Generation 1942 1955 The first generation computers used the concept of stored program and were characterized by vacuum tubes A vacuum tube is a delicate glass device that can control and amplify electronic signals The first generation computers were made using thousands of vacuum tubes and were the fastest calculating devices of their time These computers were very large in size consumed lot of electricity and generated lot of heat UNIVAC 1 was the first electronic computer of this generation and was used for business applications Examples ENIAC EDVAC UNIVAC 1 The Second Generation 1955 1964 The second generation computers were characterized by transistors A transistor is a solid state semiconductor device that revolutionized the electronic industry Transistors were smaller highly reliable consumed less electricity and generated less heat Also magnetic core memories were developed during this generation These are tiny ferrite rings that can be magnetized in either clockwise or anticlockwise direction so as to represent binary 1 or binary 0 Magnetic cores were used as primary memories
180. ture_name structure object creating object variable of structure e g struct student int roll float marks Student s Access to structure variables Structure variable can be accessed by their objects only as shown below structure object_name variable e g student roll here student is the structure and roll is the member of the structure UNION A memory location shared between two different variables of different datatypes at different times is know as Union Defining union is similar as defining the structure 48 Syntax of Union union show int i int char ch Union show obj References A reference is an alternative name for an object A reference variable provides an alias for a previously defined variable A reference declaration consists of base type an amp ampersand a reference variable name equated to a variable name the general syntax form of declaring a reference variable is as follows Type amp ref_variable variable_name Where is type is any valid C datatype ref_variable is the name of reference variable that will point to variable denoted by variable_name e g int a 10 int amp b a then the values of ais 10 and the value of b is also 10 Constant The keyword const can be added to the declaration of an object to make that object constant rather than a variable Thus the value named constant can not be altered during the program run Syntax const type name
181. ult x gt y 1 0 cout lt lt result The output of the above example would be 0 because the condition x gt y is not being satisfied hence the value 0 is being assigned to result A conditional operator can be also nested within another conditional operator Workout yourself Write a program using conditional operator to find the highest of three inputted integers Hint use nesting of conditional operator 2 1 7 Nesting of all conditional constructs In real life programming situations often all the conditional constructs are being used in a single program Any of the conditional construct can be nested within any of the other construct For example a switch case construct can nest a ladder if else if within its scope or each ladder condition of a ladder if else if may nest a switch case construct within its scope The following code snippet justifies this idea switch lt an expression gt case lt value 1 gt if lt conndition 1 gt some code else if lt condition 2 gt some code else I some code break case lt value 2 gt if lt condition 1 gt some code else if lt condition 2 gt I some code 87 else I some code break end of switch case Similarly we can have if lt condition 1 gt switch var1 case lt value1 gt break case lt value2 gt break case lt value 3 gt break else if lt condition 2 gt
182. ur different arrays would be required to keep the related information of Workers i e 1 An array to keep the Names of the Workers 2 An array to keep the Gender of the Workers 3 An array to keep the Age of the Workers 4 An array to keep the Rate of the Workers 1 Array to keep Names Ramu Hari kajri oes Bajrang Name 0 name 1 name 2 she name 19 Declaration char name 20 45 Ps 2 Array to keep Gender M M F a M Gender 0 gender 1 gender 2 a gender 19 Declaration char gender 20 3 Array to keep Age 18 22 age 0 age 1 Declaration int age 20 4 Array to keep Rate 100 120 140 m 100 rate 0 rate 1 rate 2 ee rate 19 Declaration float rate 20 Using C Structures The previous method of storing related data of Workers in different Arrays is a better a solution than storing them in several separate variables Though it provides better management of information but as the information related to a Worker increases Say along with Name Age Sex and Rate we also want to store Date Of Join Category SSN etc the need for extra Arrays arises thus Array management would be another cumbersome issue if we use Arrays to store information of a Worker Thus C provides us one of its most fascinating programming construct to handle this situation of storing huge
183. us This No will be generated when n will become anything greater than 40 Now let us convert the above flowchart 3 in a C program You may not understand all the parts of programs here so don t worry it will be described in the later part of the chapter Program 1 3 program to implement the problem described by flowchart 2 include lt iostream h gt void main intn 1 declaring a variable n to keep count of students int s1 s2 s3 s4 s5 0 declaring subject marks and initializing them with 0 float Avg 0 0 declaring variable for keeping Average of student s cout lt lt Input the number you want to check cin gt gt num Inputting value of n while n lt 40 Iteration starts here cout lt lt Input values for s1 s2 s3 s4 ands5 path CIN gt gt s1 gt gt s2 gt gt s3 gt gt s4 gt gt s5 Avg si s2 s3 s4 55 5 cout lt lt nThe average marks scored by student no lt lt n lt lt Is lt lt Avg n Incrementing the value of n by 1 Il when cyclic condition is not satisfied the program will flow out here and terminate The shaded part of the above program shows how an Iteration is implemented with a while construct of C A while construct instructs the compiler to repeat the set of statement under its scope if the logical expression here n lt 40 attached with it produces a True value If the logical statement fails to pr
184. used and supported by many companies The defining component of this operating system is the Linux kernel 3 BOSS Bharat Operating System Solutions This is an Indian distribution of GNU Linux It consists of Linux operating system kernel office application suite Bharateeya OO Internet browser Firefox multimedia applications and file sharing 4 UNIX It is a multitasking multiuser operating system originally developed in 1969 at Bell Labs It was one of the first operating systems developed in a high level language namely C Due to its portability flexibility and power UNIX is widely being used in a networked environment Today UNIX and Single UNIX Specification interface are owned and trademarked by The Open Group There are many different varieties of UNIX although they share common similarities the most popular being GNU Linux and Mac OS X 5 Solaris It is a free Unix based operating system introduced by Sun Microsystems in 1992 It is now also known as Oracle Solaris Solaris is registered as compliant with Single UNIX Specification It is quite scalable and is used on virtual machines Mobile Operating Systems Mobile OS It is the operating system that operates on digital mobile devices like smart phones and tablets It extends the features of a normal operating system for personal computers so as to include touch screen Bluetooth WiFi GPS mobile navigation camera music player and many more The most commonly us
185. ut lt lt nLeap Year else cout lt lt nNot a Leap Year getch b include lt iostream h gt include lt conio h gt void main int Number Temp b 0 cout lt lt endl lt lt Enter any number to check cin gt gt Number Temp Number int P while Temp gt 0 P Temp 10 b b P P P Temp Temp 10 if b gt Number Cout lt lt endl lt lt Armstrong no else cout lt lt Not an armstrong no getch c include lt iostream h gt int factorial int void main void int number cout lt lt Please enter a positive integer cin gt gt number if number lt 1 cout lt lt That is not a positive integer n else cout lt lt number lt lt factorial is lt lt factorial number lt lt endl int factorial int number if number lt 1 return 1 else return number factorial number 1 d include lt iostream h gt include lt conio h gt int main clrscr unsigned long first second third n int i first 0 second 1 cout lt lt how many elements gt 5 n cin gt gt n cout lt lt fibonacci series n cout lt lt first lt lt lt lt second for i 2 i lt n i third first second cout lt lt lt lt third first second Second third return 0 getch include lt iostream h gt include lt stdio h gt void main int r m i n cout lt lt Enter the number to generate
186. value Example const int uage 50 it declares a constant named as uage of type integer that holds value 50 Preprocessor Directives include is the preprocessor directive used in C programs This statement tells the compiler to include the specified file into the program This line is compiled by the processor before the compilation of the program e g include lt iostream h gt the above line include the header file iostream into the program for the smooth running of the program Compilation and Linking Compilation refers to the processing of source code files c cc or cpp and the creation of an object file This step doesn t create anything the user can actually run Instead the compiler merely produces the machine language instructions that correspond to the source code file that was compiled For instance if you compile but don t link three separate files you will have three object files created as output each with the name lt filename gt o or 49 lt filename gt obj the extension will depend on your compiler Each of these files contains a translation of your source code file into a machine language file but you can t run them yet You need to turn them into executables your operating system can use That s where the linker comes in Linking refers to the creation of a single executable file from multiple object files In this step it is common that the linker will complain about undefined function
187. variable value does not matches with any value between value 1 to value n A switch case control matches a particular switching value in a switch variable or a value generated after evaluating an expression with several values when it finds an exact match between switch variable value and case value it enters into that particular case to execute the statements under that case and then on finding a break statement it jumps out of the case and then comes out of the scope of switch case without considering other cases value Example int menu_choice 0 cin gt gt menu_choice switch menu_choice case 1 cout lt lt press key s to start the game break case 2 cout lt lt press key n to navigate through game plan break case 3 cout lt lt press key c to change the level of the game break case 4 cout lt lt press key f to fast your speed break case 5 cout lt lt press key x to exit from game break default cout lt lt you have to choose between 1 to 5 The above code implements a game menu design where inputted integer value in the switching variable menu_choice is being matched with values 1 to 5 each value representing one game action You may observe that the flow of the switch case construct is same as ladder if else if construct because it also deals with multiple paths of execution out of which a selected path gets executed If none of the conditio
188. variables to deal with whereas structures models a real life entity having some attribute 2 Arrays can have both primitive as well user defined data types There are basically two types of arrays one dimensional and multidimensional 2 dimensional 3 Functions can be passed structured datatypes as its parameter as well as they can return them 4 typedef is a special keyword to define a another name for a variable definition Sample Paper Class I Subject Computer Science Time 3Hours Maximum Marks 70 Note i All questions are compulsory 1 a What are the different functions of operating system b How the information can be used as a data explain c What do you mean by unary operators d What are the different parts of CPU Explain every part in brief e Define System Software and what are its two main types Give examples 2 f What is Booting g Which of the following are hardware and software i Capacitor ii Internet Explorer iii Hard disk iv UNIX 2 Explain the following term Give answer any six i Variable ii Token iii Array iv Debugging v Comment vi Keyword 3 a What is the difference b w while amp do while loop b What are data types What are all predefined data types in c c What will be the size of following constants qv v d Write the corresponding C expressions for the following mathematical expressions 1 i V a b ii a b p q e
189. verts source program into object program in one go and once the program is error free it can be executed later Q No 2 a An error in logic or arithmetic that must be detected at run time is called run time error For example any number is divided by zero c a 0 is run time error b if statement can perform only true condition and there is no option for false condition while if else statement can perform both true as well as false condition Example if a lt b cout lt lt a is greater than b in this code for false condition no statement is given if a lt b cout lt lt a is greater than b else cout lt lt b is greater than a here for both option either true or false output will come C d Comments in c can be given in two way Single line comment which can be given by using the symbol Example Program to find the sum of two numbers And Multi line comment which can be given by using the symbol Example this is the way To give multiline Comment e Header files are the files in which some pre programed program will be stored by the developer of the language which will help the user of to develop their program If the header file is written in angular bracket lt gt compiler will search it in C library only while in case of the header file will be searched throughout the database Q No 3 a i ii v vi are invalid amp iii iv are valid declaration b m 5 m 5 m
190. wchart 1 and then answer the following questions i Are arrows in the flowchart which represent flow emerging and proceeding in one direction in both flowcharts Yes No ii If answer to the first question is No then why not iii Let us call the flow of arrows in a particular direction a Path then how many such paths you observe in first flowchart and that in second one iv In flowchart 2 we have used rhombus What is its significance in whole flowchart So going through the questions above and answering them yourself you find that in the second flowchart is different from the first one in following respect 1 The direction of arrows in second flowchart is not always linear sometime the direction of the flow takes turns at the junction of a rhombus there are two such such turnings 2 At each rhombus junction the flow decides which way to proceed after asking a logical statement e g n is divisible by 3 thus creating several paths following which the program logic can flow In our flowchart 1 there is no such branching of paths is observed but in case of flowchart 2 we may observe two branching where from a program can flow through to reach end and terminate itself So we may now emphasize that a program not only have a linear flow but it can also have a branched flow as observed in flowchart 2 Each of these branches can be interpreted as one execution path of the same program Hence we can say that in real w
191. while x gt 0 sum sum x Xo cout lt lt The sum is lt lt sum The above code snippet finds the sum of n natural number using while loop The loop is executed till the x is greater than 0 as soon x becomes 0 the loop is terminated We observe that within the scope of the loop the value of x is decremented so that it approaches to its next previous value Thus with each iteration the value of x is added to a variable sum and is decremented by 1 Lets understand the above program with a Dry Run Let us assume that user inputs a value 4 for x then at 1 Iteration start xis 4 sum 0 i e the loop condition 4 gt 0 is evaluated as true hence it opens up the while block gt sum 0 4 4 x will be decremented by 1 thus x 3 2 Iteration start xis 3 sum 4 i e the loop condition 3 gt 0 is evaluated as true hence it opens up the while block gt sum 4 3 7 x will be decremented by 1 thus x 2 3 Iteration start xis 2 sum 7 i e the loop condition 2 gt 0 is evaluated as true hence it opens up the while block gt sum 7 2 9 x will be decremented by 1 thus x 1 4 Iteration start xis 1 sum 9 i e the loop condition 1 gt 0 is evaluated as true hence it opens up the while block gt sum 9 1 10 x will be decremented by 1 thus x 0 5 Iteration start 91 xis 0 sum 10 i e the loop condition 0 gt 0 is evaluated as false because 0 0 hence it locks up the while blo
192. workers Bajrangi M 24 140 00 Note The data member values must be supplied in the same order of the data member described in structure definition otherwise datatype mismatch error may cause Dynamic Initialization include lt iostream h gt include lt stdio h gt main Worker W 20 consider the Worker structure declared earlier for int i 0 i lt 19 i cout lt lt Input the name age gender and wages of worker number lt lt i 1 gets W i name inputting the name of worker at index cin gt gt W i age inputting the age of worker at index i cin gt gt W i gender cin gt gt W i wage 4 2 5 Function with Structure variable Just like we can pass various primitive datatypes to a function we can also pass a structure variable as function parameter arguments The benefit is that the structure carries a bundled information to the structure The prototype of such a function would be lt return_type gt function_name lt structure_name gt lt var gt Let us understand the concept with following program program 4 8 program to write a function which increases the wage of a female worker by passed percent void increaseWage Worker amp w float incr if w gender F w gender f 132 w wage w wage incr 100 Look at the highlighted parameter we have passed formal structure variable as reference so that th
193. xplained later in these tutorials Initializing arrays When declaring a regular array of local scope within a function for example if we do not specify otherwise its elements will not be initialized to any value by default so their content will be undetermined until we store some value in them The elements of global and static arrays on the other hand are automatically initialized with their default values which for all fundamental types this means they are filled with zeros In both cases local and global when we declare an array we have the possibility to assign initial values to each one of its elements by enclosing the values in braces For example int myArr 5 16 2 77 40 12071 This declaration would have created an array like this 0 1 2 3 4 billy te 2 7 o a The amount of values between braces must not be larger than the number of elements that we declare for the array between square brackets For example in the example of array myArr we have declared that it has 5 elements and in the list of initial values within braces we have specified 5 values one for each element When an initialization of values is provided for an array C allows the possibility of leaving the square brackets empty In this case the compiler will assume a size for the array that matches the number of values included between braces int myArr 16 2 77 40 12071 After this declaration array
194. y the plan should be revised Evaluation Finally the result should be examined in order to make sure that it is valid and that the problem has been solved completely Problem solving methodology As we all know there are many methods approaches available to solve a particular problem However the efficient way is to adopt a systematic method of problem solving The use of systematic method of problem solving is crucial when we use a computer to solve a problem We introduce here a seven steps problem solving method which is closely related to the software life cycle the various stages in the life of a program that can be adapted by each person to solve the problem in their own style They are given as under 1 Problem Definition Problem Analysis Design the problem Coding Program Testing and Debugging Documentation Program Maintenance Problem Definition Specification Theme Computer programs are written to solve problems posed by humankind Prior to writing a program one has to understand a description of the problem to solve This description may be very precise or vague but nevertheless it is necessary present For instance if you want to write a program to Find the average of five numbers you should ask yourself What does average mean exactly How to calculate average value Posing such questions compels you to define the problem very precisely Once you are sure of what the problem en
195. ype is in fact a null terminated array of characters So string literals enclosed between double quotes always have a null character 0 automatically appended at the end Therefore we can initialize the array of char elements called myword with a null terminated sequence of characters by either one of these two methods char myword char myword H e Ar T o 0 Xy Hello In both cases the array of characters myword is declared with a size of 6 elements of type char the 5 characters that compose the word Hello plus a final null character 0 which specifies the end of the sequence and that in the second case when using double quotes it is appended automatically Please notice that we are talking about initializing an array of characters in the moment it is being declared and not about assigning values to them once they have already been declared In fact because this type of null terminated arrays of characters are regular arrays we have the same restrictions that we have with any other array so we are not able to copy blocks of data with an assignment operation Assuming mystext is a char variable expressions within a source code like mystext Hello mystext Hello would not be valid like neither would be mystext H e T T o 0 The reason for this may become more comprehensible once you know a bit more about pointers since then it will be clarified that a

Computer Science - Kendriya Vidyalaya NDA Khadakwasala, Pune

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