IT22101 Programming for Problem Solvingunit-2.ppt

INTRODUCTION TO C
1
N.Rajkumar

Steps in learning C
Character
Set
Programs
Instructions
Tokens
2
N.Rajkumar

C Character Set
C Character Set
Execution
Character Set
Source
Character Set
Special
Characters
Digits
Alphabets Escape
Sequence
White
Spaces
3
N.Rajkumar

C Character Set (Cont)
• Source Character Set
– It is used to construct the statements in the
program.
• Executable Character Set
– These characters are employed at the time of
execution i.e. they have effects only when the
program is being executed.
4
N.Rajkumar

Source Character Set
Letters a to z ,A to Z
Digits 0 to 9
Special Characters ! @ # $ % ^ & * ( ) _ - +
= | { } [ ] etc,.
White Spaces Blank Space ,Horizontal
tab, New line, Vertical
tab etc,.
5
N.Rajkumar

Special characters
• Comma ,
• Period or dot .
• Semicolon ;
• Colon :
• Apostrophe ‘
• Quotation mark “
• Exclamation mark !
• Vertical bar |
• Back Slash
• Tilde ~
• Underscore -
• Dollar $
• Question mark ? 6
N.Rajkumar

• Ampersand &
• Caret ^
• Asterisk *
• Minus -
• Addition +
• Lesser than <
• Greater than >
• Parenthesis ()
• Bracket []
• Braces {}
• Percentage %
• Hash #
• Equal to =
• At the rate @ 7
N.Rajkumar

Executable Character Set
Characters Escape Sequence
Back Space b
Horizontal Space t
Vertical Space v
Newline n
8
N.Rajkumar

C Tokens
• The smallest element in the C language is
the token.
• It may be a single character or a sequence
of characters.
9
N.Rajkumar

C Tokens (Cont)
C Tokens
Identifiers
Eg:main,
avg
Keywords
Eg: int,
for
operators
Eg: +
-
Strings
Eg: “ab”
spI
symbol
Eg: #
$ %
Constants
Eg:17,
15.5
10
N.Rajkumar

Executing a C Program
Creating the Program
Compilation
Linking
Execution
11
N.Rajkumar

Executing a C Program (Cont)
• Enter the program in a C editor.
• Save the program (File  Save) or F2.
Use the extension .c for saving the file.
Eg: sample.c
• Compile the program(Compile  Compile)
or Alt+F9.
• Run the program(Run  Run) or Ctrl+F9.
12
N.Rajkumar

Structure of C program
DOCUMENTATION SECTION
PREPROCESSOR SECTION
DEFINITION SECTION
GLOBAL DECLARATION SECTION
main()
{
Declaration part;
Executable Part;
}
sub program section
{
Body of the subprogram;
}
13
N.Rajkumar

• Documentation Section
– It contains the comment lines.
• Preprocessor Section
– It is used to link library files.
• Global Declaration Section
– The Global declaration section comes at the
beginning of the program and they are visible
to all parts of the program.
• Declaration Section
– It describes the data to be used within the
function.
• Executable Part
– It contains the valid statements. 14
N.Rajkumar

C Programs
 C program may have many functions.
 One and only one of the functions MUST BE
named main.
 main is the starting point for the program.
 main and other functions in a program are
divided into two sections, declaration
section and statement section.
15
N.Rajkumar

Preprocessor Directives
• Special instructions to the preprocessor
that tells how to prepare the program for
compilation
• E.g: include : tells the processor to
include information from selected libraries
known as header files e.g. <stdio.h>
16
N.Rajkumar

Comments (Program documentation)
 The compiler simply ignores comments
when it translates the program into
executable code.
 To identify a comments, C uses opening
/* and closing */ comment tokens.
17
N.Rajkumar

Comments (Cont)
 Comments can appear anywhere in a
program.
 Comments are also found wherever it is
necessary to explain a point about a code.
 Comments cannot be nested in C i.e. you
cannot have comments inside comments.
18
N.Rajkumar

C program
/* Example program in C*/ Comments
# include <stdio.h>Preprocessor Section
#include<conio.h>
Global Declaration
void main ()
{ Local declaration
printf (“Hello World! n”); Statements
getch();
}
Output :
Hello World 19
N.Rajkumar

C Tokens
• Identifiers
• Keywords
• Constants
• Operators
• Special symbols
20
N.Rajkumar

Identifiers
• Identifiers are names given to various
program elements such as variables,
functions and arrays etc,.
• Eg: #define N 10
#define a 15
Here N and a are user defined identifiers.
21
N.Rajkumar

Rules for naming identifier
• First character must be alphabetic or
underscore.
• Must consist only of alphabetic characters,
digits, or underscores.
• Only the first 31 characters of an identifier are
significant and are recognized by the compiler.
• Cannot use a keywords or reserved word (e.g.
main, include, printf & scanf etc.).
• No space are allowed between the identifiers
etc,.
• C is case sensitive, e.g. My_name  my_name.
22
N.Rajkumar

Examples of Valid and Invalid Names
Valid Names Invalid Names
a a1 $sum /* $ is illegal */
student_name stdntNm 2names /* Starts with 2 */
_aSystemName _anthrSysNm stdnt Nmbr /* no spaces */
TRUE FALSE int /* reserved word */
23
N.Rajkumar

Variables
• Variable is an identifier that is used to
represent some specified type of
information.
• Eg: x=3
• Here x is variable.
24
N.Rajkumar

Keywords
• It is a reserved words.
• Cannot be used for anything else.
• Examples:
– int
– while
– for etc,.
25
N.Rajkumar

Keywords
Auto register Continue
Double typedef For
Int Char signed
Struct extern void
Break return Default
Else union Goto
Long Const sizeof
Switch Float do
Case short If
Enum unsigned
Static While
26
N.Rajkumar

Constants
• It is an entity whose value does not
changes during the execution.
• Eg: x=3
• Here 3 is a constant.
27
N.Rajkumar

Types
• Numeric constants
• Character constant
28
N.Rajkumar

Constants
Constants
Character Constants
Numeric Constants
Real
Constant
Integer
Constant
String
Constant
Single
Character
Constant
29
N.Rajkumar

Numeric constants
Integer constants
• It is formed using a sequence of digits.
Decimal - 0 to 9 .
Octal - 0 to 7.
Hexa - 0 to 9 ,A to F
Eg: 10,75 etc.
30
N.Rajkumar

Rules for defining Integer Constant
• It must have atleast one digit.
• Decimal point are not allowed.
• No blank space or commas are allowed.
• It can be either positive or negative. Etc,.
31
N.Rajkumar

Numeric constants
Real constants
• It is formed using a sequence of digits but
it contain decimal point.
• length, height, price distance measured in
real number
Eg: 2.5, 5.11, etc.
32
N.Rajkumar

Character constants
Single character constant
– A character constant is a single character
they also represented with single digit or a
single special symbol which is enclosed in
single quotes.
– Eg: ‘a’, ‘8’,’_’etc.
33
N.Rajkumar

Character constants
String constants
• String constant are sequence of characters
enclosed with in double quote.
• Eg: “Hello” ,”444”,”a” etc,.
34
N.Rajkumar

Operators
• An operator is a symbol that specifies an
operation to be performed on the
operands.
• Eg: a + b
+ is an operator.
a,b are operands.
35
N.Rajkumar

Data Types
 A Data type is the type of data that are
going to access within the program.
36
N.Rajkumar

DATA TYPES
DATA TYPES
PRIMARY DERIVED
USER
DERIVED
CHARACTER INTEGER REAL
Array, Function,
Pointer
Structure, union
….
char
short int,
int, long int
Float,
double
long double 37
N.Rajkumar

integer
 A number without a fraction part : integral
number.
 C supports three different sizes of the
integer data type :
 short int
 int
 long int
38
N.Rajkumar

Floating Point
 A floating-point type is a number with a
fractional part, e.g. 56.78
 Floating point numbers are stored using
4 Byte.
 Types
 Float
 Double
 long double
39
N.Rajkumar

character
• Character are generally stored using 8
bits(1 Byte) of the internal storage.
40
N.Rajkumar

void
 The void type has no values and no
operations.
 Both the set of values and the set of
operations are empty.
41
N.Rajkumar

Variable Declaration
 To create a variable, you must specify the type and
then its identifier :
 Integer
int a;
a=10;
int a=10;
int a,b;
a=10;
b=5;
int a=10,b=5;
42
N.Rajkumar

 Float
float a;
a=10.5;
float a=10.5;
float a,b;
a=10.5;
b=5.5;
float a=10.5,b=5.5;
43
N.Rajkumar

 Character
char a;
a=‘x’;
char a=‘x’;
char a,b;
a=‘x’;
b=‘y’;
char a=‘x’,b=‘y’;
44
N.Rajkumar

 String
char a[6];
a=“NAFEES”;
char a[6]=“NAFEES”;
Representation of string a
N
a[0]
A
a[1]
F
a[2]
E
a[3]
E
a[4]
S
a[5]
45
N.Rajkumar

Entire Data types in c:
Data type Size(bytes) Range Format string
Char 1 128 to 127 %c
Unsigned char 1 0 to 255 %c
Short or int 2 -32,768 to 32,767 %i or %d
Unsigned int 2 0 to 65535 %u
Long 4 -2147483648 to 2147483647 %ld
Unsigned long 4 0 to 4294967295 %lu
Float 4 3.4 e-38 to 3.4 e+38 %f or %g
Double 8 1.7 e-308 to 1.7 e+308 %lf
Long Double 10 3.4 e-4932 to 1.1 e+4932 %lf 46
N.Rajkumar

Basic C programs
#include<stdio.h>//program to display given data
#include<conio.h>
void main()
{
int a=10;
float b=10.88;
char c=‘$’;
char d[6]=“Nafees”;
clrscr();
printf(“Integer value : %dn”,a);
printf(“Float value : %fn”,b);
printf(“Character : %cn”,c);
printf(“String : %s”,d);
getch();
}
OUTPUT
Integer value : 10
Float value : 10.88
Character : $
String : Nafees
47
N.Rajkumar

Basic C programs
#include<stdio.h>//program to display given data from user
#include<conio.h>
void main()
{
int a;
float b;
char c;
char d[6];
clrscr();
printf(“Enter a integer value : “);
scanf(“%d”,&a);
printf(“Enter a float value : “);
scanf(“%f”,&b);
printf(“Enter a character : “);
scanf(“%c”,&c);
printf(“Enter a string : “);
scanf(“%s”,d);
OUTPUT
Enter a integer value :12
Enter a float value : 5.34
Enter a character : h
Enter a string : Nafees
Integer value : 12
Float value : 5.34
Character : h
String : Nafees
printf(“Integer value : %dn”,a);
printf(“Float value : %fn”,b);
printf(“Character : %cn”,c);
printf(“String : %s”,d);
getch();
}
48
N.Rajkumar

Types of Operator
1. Arithmetic operator
2. Relational operator
3. Logical operator
4. Assignment operator
5. Short hand assignment operator
6. Increment or decrement operator(unary)
7. Comma operator
8. Conditional operator
49
N.Rajkumar

Arithmetic operator
• It is used to carry out arithmetic
operations
NAME OPERATOR
ADDITION +
SUBTRACTION -
MULTIPLICATION *
DIVISION /
MODULUS
(REMAINDER)
%
50
N.Rajkumar

SAMPLE PROGRAM
#include<stdio.h> // Header File
#include <conio.h>
void main ( ) /* main is the starting of every c program */
{
int a=5,b=2; //Local Declaration
clrscr( );
printf(“Addition : %dn”,(a+b));
printf(“Subtraction : %dn”,(a-b));
printf(“Multiplication : %dn”,(a*b));
printf(“Division : %dn”,(a/b));
printf(“Modulus(remainder): %d”,(a%b));
getch( );
}
OUTPUT
Addition : 7
Subtraction : 3
Multiplication : 10
Division :2
Modulus(remainder):1
51
N.Rajkumar

Division operator on Different
Data Type
Operation Result Example
int/int int 5/2 = 2
int/real real 5/2.0 = 2.5
real/int real 5.0/2 = 2.5
real/real real 5.0/2.0 = 2.5
52
N.Rajkumar

Relational operator
• It is used to compare two or more
operands and returns 1 if true else return 0
NAME OPERATOR
Less than <
Less than or equal to <=
Greater than >
Greater than or equal to >=
Equal to ==
Not equal to !=
53
N.Rajkumar

Relational Operator…
#include<stdio.h>
#include <conio.h>
void main()
{
clrscr();
printf(“n5!=3:%d”,(5!=3));
printf(“n5<=3:%d”,(5<=3));
printf(“n5>=3:%d”,(5>=3));
printf(“n5<7 :%d”,(5<7));
printf(“n5>4 :%d”,(5>4));
getch();
}
OUTPUT
5!=3 : 1
5<=3 : 0
5>=3 : 1
5<7 : 1
5>4 : 1
54
N.Rajkumar

Logical operator
• It is used to perform logical operations
NAME OPERATOR
AND &&
OR ||
NOT !
55
N.Rajkumar

Sample program
#include<stdio.h>
#include <conio.h>
void main ( )
{
clrscr( );
printf(“n(5<=8)&&(4>=2):%d”,((5<=8)&&(4>=2)));
printf(“n(5>=3)||(6<4):%d”,((5>=3)||(6<4)));
printf(“n!(7==7):%d”,!(7==7));
getch( );
} OUTPUT
(5<=8)&&(4>=2) : 1
(5>=3)||(6<4) : 1
!(7==7) : 0
56
N.Rajkumar

Assignment operator
• It is used to assign a value or
expression etc to a variable.
• Eg: a =10.(assignment operator ‘=‘
assigns value 10 to variable a.
a = b
a = b + c etc,.
57
N.Rajkumar

Shorthand Assignment Operator
58
N.Rajkumar

Increment & Decrement Operator
NAME OPERATOR
Increment operator ++
Decrement operator --
Pre Increment Post Increment
int a=10;
++a
Now value of a is 11
int a=10;
a++
Now value of a is 11
Pre decrement Post decrement
int a=10;
--a
Now value of a is 9
int a=10;
a--
Now value of a is 9
59
N.Rajkumar

#include<stdio.h>
#include<conio.h>
void main()
{
int a,b;
clrscr();
printf(“Enter a & b value : n”);
scanf(“%d%d”,&a,&b);
printf(“Value of a & b before increment : %d %dn”,a,b);
printf(“Value of a & b after increment : %d
%dn”,a++,b++);
printf(“Value of a & b after decrement : %d %dn”,a--,b—);
getch();
} 60
N.Rajkumar

OUTPUT
Enter a & b value :
6
9
Value of a & b before increment : 6 9
Value of a & b after increment : 7 10
Value of a & b after decrement : 5 8
61
N.Rajkumar

Conditional Operator (or)
Ternary Operator
• It is used to checks the condition and
execute the statement depending on the
condition.
• Eg: C = a > b ? a:b
62
N.Rajkumar

Sample Program
#include<stdio.h>
#include <conio.h>
void main ( )
{
int a=5,b=8,c;
clrscr( );
c = a>b?a:b; //Conditional operator
printf(" n The Larger Value is %d",c);
getch( );
}
OUTPUT
The Larger Value is 8
63
N.Rajkumar

Output
OUTPUT
64
N.Rajkumar

Special Operator
• comma operator ( , )
EX: int a,b;
65
N.Rajkumar

Expression
• An expression represent data item such as
variable, constant are interconnected
using operators.
• Eg:
Expression C Expression
a + b + c a + b + c
a2+b2 a*a + b*b
66
N.Rajkumar

Precedence Operator
High * , / , %
Low + , -
67
N.Rajkumar

Type Conversion
• Converting the type of an expression from
one type to another type.
Eg: x = (int)10.45
68
N.Rajkumar

Sample Program
#include<stdio.h>
#include <conio.h>
void main ( )
{
int c;
clrscr( );
c=(int)10.45;
printf("nOutput is:%d",c);
getch( );
}
OUTPUT
Output is:10
69
N.Rajkumar

PROGRAM CONTROL STRUCTURES
• Depending upon the sequence of the execution of
statements, the control structures are categorized as
follows:
• Categories:
• Sequential structure
– In which instructions are executed in sequence.
• Selection structure
– In which instruction are executed based on the result
of some condition.
• Iteration structure
– In which instruction are executed repeatedly.
70
N.Rajkumar

Sequential STRUCTURE
• It allows the program to flow in
sequence
START
Statement 1
Statement 2
Statement N
STOP
71
N.Rajkumar

SELECTION STRUCTURE
• It allows the program to make a choice
from alternative paths.
• C provide the following selection
structures
– if statement
– if … else statement
– Nested if … else statement
72
N.Rajkumar

if Statement
Syntax
if (condition is true)
{
Statements;
}
If
condition
False
True
Statements
73
N.Rajkumar

if…else Statement
Syntax
if (condition)
{
True statements;
}
else
{
False statements;
}
If
Condition
True False
True
statements
False
statements
74
N.Rajkumar

Nested if…else
Condition
1
Statements
Condition
2
Statements
Condition
3
Statements Statements
TRUE
TRUE
TRUE FALSE
FALSE
FALSE
75
N.Rajkumar

Nested if…else
Syntax
IF (condition1)
{
statements;
}
else if (condition2)
{
statements;
}
else if (condition3)
{
statements;
}
else
{
statements;
}
76
N.Rajkumar

Iteration structure
• It is used to execute some instructions
several time based on some condition.
– while
– do…while
– for
77
N.Rajkumar

while Loop
Syntax
.
while (condition)
{
.
Body of the loop;
.
} Body of The loop
condition
False
True
78
N.Rajkumar

do…while Loop
Syntax
do
{
Body of the loop
}while (condition);
Body of The loop
condition
False
True
79
N.Rajkumar

for loop
Syntax
for (initialization; test condition; Increment/Decrement)
{
Body of the loop
}
80
N.Rajkumar

for loop
Initialization
condition False
Body of the loop
Inc / Decrement
81
N.Rajkumar

Nested for loop
Syntax
for (initi; cond; Inc/Dec)
{
{
Body of the loop
}
}
82
N.Rajkumar

DECISION MAKING & BRANCHING
• if statement
• if else statement
• Nested if else statement
• switch statement
• Conditional statement
• goto statement
• break statement
• continue statement
Selection statements
Unconditional
statements
83
N.Rajkumar

if statement (Simple if)
Syntax
{
Statements;
}
84
N.Rajkumar

if statement (Simple if)
#include<stdio.h>
#include <conio.h>
void main ( )
{
int a;
clrscr( );
printf("nEnter a number:");
scanf("%d",&a);
if(a>10)
{
printf(" n a is greater than 10");
}
getch( );
}
OUTPUT
Enter the number: 12
a is greater than 10
85
N.Rajkumar

if else statement
Syntax
{
Statements;
}
else
{
Statements;
} 86
N.Rajkumar

if else statement
#include<stdio.h>
#include <conio.h>
void main ( )
{
int a;
clrscr( );
printf("nEnter a number:");
scanf("%d",&a);
if(a>10)
{
printf(" n a is greater than 10");
}
else
{
printf(" n a is not greater than 10");
}
getch( );
}
OUTPUT
Enter the number: 12
a is greater than 10
Enter the number: 1
a is not greater than10
87
N.Rajkumar

Nested if else statement
Syntax
{
Statements;
}
else if (condition is true)
{
Statements;
}
else if (condition is true)
{
Statements;
}
else
{
Statements;
}
88
N.Rajkumar

Nested if else statement
#include<stdio.h>
#include<conio.h>
void main()
{
int m1,m2,m3;
float avg;
printf("nEnter the marks:");
scanf("%d%d%d",&m1,&m2,&m3);
avg=(m1+m2+m3)/3;
printf("n The average is:%f",avg);
printf("n The Grade is:");
if(avg>=60)
{
printf("First class");
} 89
N.Rajkumar

else if(avg>=50)
{
printf("Second class");
}
else if(avg>=35)
{
printf("Third class");
}
else
{
printf("Fail");
}
getch();
}
OUTPUT
Enter the marks:65
75
70
The average is:70.00
The Grade is: First
class
90
N.Rajkumar

Nested if else
#include <stdio.h> //Program to find leap year
#include<conio.h>
void main()
{
int year;
printf("Enter a year to check if it is a leap year : n");
scanf("%d", &year);
if ( year%400 == 0)
printf("%d is a leap year.n", year);
else if ( year%100 == 0)
printf("%d is not a leap year.n", year);
else if ( year%4 == 0 )
printf("%d is a leap year.n", year);
else
printf("%d is not a leap year.n", year);
getch();
}
OUTPUT
Enter a year to check
if it is a leap year
:2012
2012 is a leap year
91
N.Rajkumar

switch statement
Syntax
switch (expression)
{
case constant 1:
block1;
break;
case constant 2:
block2;
break;
.
.
default :
default block;
break;
}
Case 1
Case 2
Default
case
Switch
92
N.Rajkumar

switch statement
#include<stdio.h>
#include<conio.h>
void main()
{
int a,b,c,n;
clrscr();
printf("nEnter the value of a,b:n");
scanf("%d%d",&a,&b);
printf("nMENU");
printf("n1.ADDn2.SUBn3.MULTIPLYn4.EXIT");
printf("nEnter the choice:");
scanf("%d",&n);
93
N.Rajkumar

switch(n)
{
case 1:
c=a+b;
printf("nThe result of Addition is:%d",c);
break;
case 2:
c=a-b;
printf("nThe result of Subtraction is:%d",c);
break;
94
N.Rajkumar

case 3:
c=a*b;
printf("nThe result of Multiplication is:%d",c);
break;
case 4:
exit(0);
break;
default:
printf(“Wrong Choice”);
}
getch();
}
OUTPUT
Enter the value of a,b:
5
6
MENU
1.ADD
2.SUB
3.MULTIPLY
4.EXIT
Enter the choice:1
The result of Addition is:11
95
N.Rajkumar

Conditional Statement
• It uses conditional operator (?)
#include<stdio.h>
#include<conio.h>
void main()
{
int n;
printf(“Enter a number : “);
scanf(“%d”,&n);
(n%2==0)?printf(“even”):printf(“odd”);
getch();
}
OUTPUT
Enter a number : 3
odd
96
N.Rajkumar

goto statement
• When a goto statement is encountered, the control
is transferred to the label.
goto label;
…………
…………
…………
label:
…………
97
N.Rajkumar

goto statement
#include<stdio.h>
#include<conio.h>
void main()
{
int x;
clrscr();
printf(“Enter a number to find odd or even no : “);
scanf(“%d”,&x);
if(x%2==0)
goto even;
else
goto odd;
98
N.Rajkumar

goto statement
even:
printf(“%d is an even no”,x);
return;
odd:
printf(“%d is an odd no”,x);
return;
OUTPUT
Enter a number to find odd or even no :5
5 is an odd no
99
N.Rajkumar

#include<stdio.h>
#include<conio.h>
void main()
{
int a,b;
clrscr();
printf(“Enter two value to subtract : n”);
scanf(“n%d%d”,&a,&b);
if(a>b)
{
printf(“Subtracted value is : %dn”,(a-b));
}
else
{
break;
}
}
OUTPUT
Enter two value to subtract :
5
3
Subtracted value is : 2
When break statement is
encountered inside any block or loop,
control automatically passes to the first
statement after the block or loop
break statement
100
N.Rajkumar

#include<stdio.h>
#include<conio.h>
void main()
{
int a;
clrscr();
for(a=1;a<=10;a++)
{
if((a==5)||(a==7))
continue;
else
printf(“%dn”,a);
}
}
OUTPUT
1
2
3
4
6
8
9
10
Continue statement terminates the
current loop iteration & persist the loop with
next iteration
continue statement
101
N.Rajkumar

• Loop:
–A loop is defined as a block of statements
which are repeatedly executed for certain
no of times.
• Types of Loops in C
–while loop
–do while loop
–for loop(simple & nested)
Looping Statements
102
N.Rajkumar

• It is an entry controlled loop works only when the condition is
true
• Syntax:
while (condition)
{
.
Body of the loop;
.
}
while loop
103
N.Rajkumar

#include<stdio.h> //program to print even no
#include<conio.h>
void main()
{
int n,i;
printf(“Enter the limit : “);
scanf(“%d”,&n);
i=1;
while (i<=n)
{
if(i%2==0)
{
printf(“%dt”,i);
}
i++;
}
}
while loop
OUTPUT
Enter the limit : 10
2 4 6 8 10
104
N.Rajkumar

#include<stdio.h> //program to calculate factorial of given no
#include<conio.h>
void main()
{
int i=1,fact=1,n;
printf("nEnter the Number:");
scanf("%d",&n);
while(i<=n)
{
fact =fact *i;
i++;
}
printf("n The value of %d! is:%d",n,fact);
getch();
}
while loop
OUTPUT
Enter the Number:3
The value of 3! is: 6
105
N.Rajkumar

#include<stdio.h> //program to reverse a number and to check
#include<conio.h>// whether it is palindrome or not
void main()
{
int n,rev=0;`
clrscr();
printf(“Enter a number to reverse : “);
scanf(“%d”,&n);
while(n!=0)
{
rev=rev*10;
rev=rev+(n%10);
n=n/10;
}
printf(“Reverse of given no is : %dn”,rev);
while loop
OUTPUT
Enter a number to
reverse : 452
Reverse of given
number is : 254
Not Palindrome
if(n==rev)
{
printf(“Palindrome”);
}
else
{
printf(“Not Palindrome”);
}
getch():
}
106
N.Rajkumar

#include<stdio.h> //program to find sum of digits
#include<conio.h>
void main()
{
int r=0,sum=0,n;
printf("nEnter the no:");
scanf("%d",&n);
while(n>0)
{
r=n%10;
sum=sum+r;
n=n/10;
}
printf("sum of the digits is:%d",sum);
getch():
}
while loop
OUTPUT
Enter the no:156
sum of the digits is:12
107
N.Rajkumar

#include<stdio.h> //program to find armstrong number
#include<conio.h>
void main()
{
int r=0,sum=0,n,a;
printf("nEnter the number:");
scanf("%d",&n);
a=n;
while(n>0)
{
r=n%10;
sum=sum+r*r*r;
n=n/10;
}
if(a==sum)
printf("nIt is an armstrong number");
else
printf("nIt is not an armstrong number");
getch();
}
OUTPUT
Enter the number:153
It is an armstrong number
108
N.Rajkumar

• It is an exit controlled loop. It proceeds its first iteration without
checking the loop condition and proceeds next iteration by
checking the condition.
• Syntax:
do
{
.
Body of the loop;
.
}while (condition);
do while loop
109
N.Rajkumar

#include<stdio.h> //program to print even no
#include<conio.h>
void main()
{
int n,i;
printf(“Enter the limit : “);
scanf(“%d”,&n);
i=1;
do
{
if(i%2==0)
{
printf(“%dt”,i);
}
i++;
}while (i<=n);
}
do while loop
OUTPUT
Enter the limit : 10
2 4 6 8 10
110
N.Rajkumar

#include<conio.h>
void main()
{
int i=1,fact=1,n;
scanf("%d",&n);
do
{
fact =fact *i;
i++;
}while (i<=n);
getch();
}
do while loop
OUTPUT
Enter the Number:3
111
N.Rajkumar

do while loop //program to generate fibonacci series
OUTPUT
Enter the range : 10
0
1
1
2
3
5
8
#include<stdio.h>
#include<conio.h>
void main()
{
int a,b,c,r;
clrscr();
printf(“Enter the range : “);
scanf(“%d”,&r);
a=0,b=1;
printf(“%d”,a);
printf(“n%d”,b);
printf(“n”);
c=0;
do
{
c=a+b;
if(c<=r)
printf(“%dn”,c);
a=b;
b=c;
}while(c<=r);
getch();
} 112
N.Rajkumar

for loop
Syntax:
for (initialization; test condition; Increment/Decrement)
{
Body of the loop
}
113
N.Rajkumar

#include<stdio.h> //program to generate number from 1 to n
#include<conio.h>
void main()
{
int i,n;
printf("nEnter the limit : ");
scanf("%d",&n);
for(i=1;i<=n;i++)
{
printf(“%dn”,i);
}
getch();
}
for loop
OUTPUT
Enter the limit : 5
1
2
3
4
5
114
N.Rajkumar

#include<conio.h>
void main()
{
int i,fact=1,n;
scanf("%d",&n);
for(i=1;i<=n;i++)
{
fact =fact *i;
}
getch();
}
for loop
OUTPUT
Enter the Number:3
115
N.Rajkumar

#include<stdio.h> //program to generate given multiplication table
#include<conio.h>
void main()
{
int i,tab,n,res;
printf("nEnter the multiplication table:");
scanf("%d",&tab);
printf("nEnter the limit of multiplication table:");
scanf("%d",&n);
for(i=1;i<=n;i++)
{
res=i*tab;
printf("%d * %d : %dn”,i,tab,res);
}
getch();
}
for loop
OUTPUT
Enter the multiplication table : 2
Enter the limit of multiplication
table : 4
1 * 2 : 2
2 * 2 : 4
3 * 2 : 6
4 * 2 : 8
116
N.Rajkumar

#include<stdio.h>//program to calculate student marks & average using for loop
#include<conio.h>
void main()
{
int n,s1,s2,s3,s4,s5,tot;
float avg;
clrscr();
printf(“Enter no of students : ”);
scanf(“%d”,&n);
printf(“Enter marks of five subjects : n”)
for(i=1;i<=n;i++)
{
printf(“Enter student %d marksn”,i);
scanf(“%d%d%d%d%d”,&s1,&s2,&s3,&s4,&s5);
tot=s1+s2+s3+s4+s5;
avg=tot/5;
printf(“Total : %dnAverage : %f”,tot,avg);
}
getch();
}
for loop
117
N.Rajkumar

• Definition of prime number:
– A natural number greater than one has not any other divisors except
1 and itself. In other word we can say which has only two divisors 1
and number itself.
– For example: 5. Their divisors are 1 and 5.
for loop
118
N.Rajkumar

#include<stdio.h>//program to check whether the given no is prime or not
#include<conio.h>
void main()
{
int n, i, c = 0;
printf("Enter a number :");
scanf("%d", &n);
for (i = 1; i <= n; i++)
{
if (n % i == 0)
{
c++;
}
}
if (c == 2)
printf(“Given no is a Prime number");
else
printf(“Given no is not a Prime number");
getch();
}
for loop
OUTPUT
Enter a number : 7
Given no is a Prime number
119
N.Rajkumar

Nested for loop
Syntax
{
{
Body of the loop
}
}
120
N.Rajkumar

#include<stdio.h> //program to generate numbers in triangle
#include<conio.h>
void main()
{
int i`,j,n;
scanf("%d",&n);
for(i=1;i<=n;i++)
{
for(j=1;j<=i;j++)
{
printf(“%d”,i);
}
printf(“n”);
}
getch();
}
Nested for loop
OUTPUT
Enter the limit : 5
1
22
333
4444
55555
121
N.Rajkumar

#include<stdio.h> //program to generate stars(*) in triangle
#include<conio.h>
void main()
{
int I,j,n;
scanf("%d",&n);
for(i=1;i<=n;i++)
{
for(j=1;j<=i;j++)
{
printf(“*”);
}
printf(“n”);
}
getch();
}
Nested for loop
OUTPUT
Enter the limit : 5
*
**
***
****
*****
122
N.Rajkumar

Swapping without using third
variable
#include<stdio.h>
#include <conio.h>
void main ( )
{
int a,b;
clrscr( );
printf(" nEnter the value of a:");
scanf("%d",&a);
printf(" nEnter the value of b:");
scanf("%d",&b);
124
N.Rajkumar

a=a+b;
b=a-b;
a=a-b;
printf(" nThe value of a is:%d",a);
printf(" nThe value of b is:%d",b);
getch( );
}
Output:
Enter the value of a:5
Enter the value of b:6
The value of a is:6
The value of b is:5
125
N.Rajkumar

Quadratic Equation
#include<stdio.h>
#include <conio.h>
#include<math.h>
void main ( )
{
int a,b,c,d,r1,r2;
clrscr( );
printf(" nEnter the value of a:");
scanf("%d",&a);
printf(" nEnter the value of b:");
scanf("%d",&b);
printf(" nEnter the value of c:");
scanf("%d",&c);
d=b*b-4*a*c;
126
N.Rajkumar

if(d>=0)
{
r1=(-b+sqrt(d))/(2*a);
r2=(-b-sqrt(d))/(2*a);
printf(" nThe roots are %d,%d",r1,r2);
}
else
{
printf(" nThe roots are imaginary");
}
getch( );
}
127
N.Rajkumar

Output
Enter the value of a:4
Enter the value of b:5
Enter the value of c:6
The roots are imaginary
128
N.Rajkumar

IT22101 Programming for Problem Solvingunit-2.ppt

More Related Content

Similar to IT22101 Programming for Problem Solvingunit-2.ppt (20)

Recently uploaded (20)

IT22101 Programming for Problem Solvingunit-2.ppt