The document contains 24 C programming examples demonstrating various programming concepts like input/output, arithmetic operations, conditional statements, loops, functions, strings, arrays and matrices. The examples include programs to calculate sum and average, area of shapes, simple and compound interest, employee salary calculation, swapping values, finding largest number, checking vowels, printing tables, factorials, reversing numbers, string operations and matrix addition.

1. 1. Program to Find Sum and Average of Three Real Numbers.
#include <stdio.h>
#include<conio.h>
main()
{
float a, b, c, sum, avg;
printf("nEnter value of three numbers: ");
scanf("%f %f %f", &a, &b, &c);
sum = a + b + c;
avg = sum / 3;
printf("nSum = %f", sum);
printf("nAverage = %f", avg);
getch();
}
Output:
1

2. 2. Program to Find Area of Square & Circumference of a Circle.
#include <stdio.h>
#include<conio.h>
#define PI 3.142
main()
{
float len, r, area, circum;
printf("nEnter length of a square: ");
scanf("%f", &len);
area = len * len;
printf("nEnter radius of a circle: ");
scanf("%f", &r);
circum = 2 * PI * r;
printf("nArea of square = %f", area);
printf("nCircumference of circle = %f", circum);
getch();
}
Output:
2

3. 3. Program to Find Area of a Triangle using Hero’s Formula .
#include <stdio.h>
#include<conio.h>
#include <math.h>
main()
{
float a, b, c, s, area;
printf("nEnter three sides of a triangle: ");
scanf("%f %f %f", &a, &b, &c);
s = (a + b + c) / 2;
area = sqrt(s * (s - a) * (s - b) * (s - c));
printf("nnArea of triangle: %f", area);
getch();
}
Output:
3

4. 4. Program to find Simple Interest and Compound Interest.
SI = (p * r * t) / 100
CI = p * pow((1 + r/100), t) - p
#include <stdio.h>
#include<conio.h>
#include <math.h>
main()
{
float p, r, t, si, ci;
printf("nEnter priciple, rate and time: ");
scanf("%f %f %f", &p, &r, &t);
si = (p * r * t) / 100;
ci = p * pow((1 + r/100), t) - p;
printf("nnSimple Interest: %f", si);
printf("nnCompound Interest: %f", ci);
getch();
}
Output:
4

5. 5. Basic salary of an employee is input through the keyboard. The DA
is 25% of the basic salary while the HRA is 15% of the basic
salary. Provident Fund is deducted at the rate of 10% of the gross
salary(BS+DA+HRA).
Program to Calculate the Net Salary.
#include <stdio.h>
#include<conio.h>
main()
{
float basic_sal, da, hra, pf, gross_sal, net_sal;
printf("nEnter basic salary of the employee: Rs. ");
scanf("%f", &basic_sal);
da = (basic_sal * 25)/100;
hra = (basic_sal * 15)/100;
gross_sal = basic_sal + da + hra;
pf = (gross_sal * 10)/100;
net_sal = gross_sal - pf;
printf("nnNet Salary: Rs. %f", net_sal);
getch();
}
Output:
5

6. 6.Program to Swap Values of Two Variables Without using 3rd Variable
#include <stdio.h>
#include<conio.h>
main()
{
int a, b, temp;
printf("nEnter any two numbers: ");
scanf("%d %d", &a, &b);
printf("nnBefore Swapping:n");
printf("na = %dn", a);
printf("nb = %dn", b);
a = a + b;
b = a - b;
a = a - b;
printf("nnAfter Swapping:n");
printf("na = %dn", a);
printf("nb = %dn", b);
getch();
6
}
Output:

7. 7. Program to Swap Values of Two Variables using Third Variable
#include <stdio.h>
#include<conio.h>
main()
{
int a, b, temp;
printf("nEnter any two numbers: ");
scanf("%d %d", &a, &b);
printf("nnBefore Swapping:n");
printf("na = %dn", a);
printf("nb = %dn", b);
temp = a;
a = b;
b = temp;
printf("nnAfter Swapping:n");
printf("na = %dn", a);
printf("nb = %dn", b);
getch();
7
}
Output:

8. 8. Program to Find Largest of Three Numbers .
#include <stdio.h>
#include<conio.h>
main()
{
int a, b, c;
printf("nEnter three numbers: ");
scanf("%d %d %d", &a, &b, &c);
if (a>b && a>c)
printf("nn%d is greater", a);
else if (b>a && b>c)
printf("nn%d is greater", b);
else
printf("nn%d is greater", c);
getch();
}
Output:
8

9. 9. Program to Check Whether a Character is a Vowel or not by using
switch Statement
#include <stdio.h>
#include<conio.h>
main()
{
char ch;
printf("nEnter any character: ");
scanf("%c", &ch);
switch (ch)
{
case 'a':
case 'A':
printf("nn%c is a vowel", ch);
break;
case 'e':
case 'E':
printf("nn%c is a vowel", ch);
break;
case 'i':
case 'I':
printf("nn%c is a vowel", ch);
break;
case 'o':
case 'O':
printf("nn%c is a vowel", ch);
break;
case 'u':
case 'U':
printf("nn%c is a vowel", ch);
break;
default:
printf("nn%c is not a vowel", ch);
}
getch();
}
9

10. Output:
10

11. 10. Program to Find the Sum of First 100 Positive Integers .
#include <stdio.h>
#include<conio.h>
main()
{
int i, sum=0;
printf("ntSum of first 100 positive numbersn");
for(i=0; i<=100; i++)
sum = sum + i;
printf("nSum = %d", sum);
getch();
}
Output:
11

12. 11. Program to Find the Sum of Even and Odd Numbers from First 100
Positive Integers
#include <stdio.h>
#include<conio.h>
main()
{
int i, sumEven=0, sumOdd=0;
for (i=0; i<=100; i++)
if (i%2 == 0)
sumEven = sumEven + i;
else
sumOdd = sumOdd + i;
printf("nSum of first even 100 numbers: %dn", sumEven);
printf("nSum of first odd 100 numbers: %dn", sumOdd);
getch();
}
Output:
12

13. 12. Program to Print a Table of any Number .
#include <stdio.h>
#include<conio.h>
main()
{
int n, mul, i;
printf("nEnter any no.: ");
scanf("%d", &n);
for(i=1; i<=10; i++)
{
mul = n*i;
printf("nn%dtxt%dt=t%d", n, i, mul);
}
getch();
}
Output:
13

14. 13. Program to Print the Numbers, Which are Divisible by 3 and 5 from
First 100 Natural Numbers
#include <stdio.h>
#include<conio.h>
main()
{
int i;
printf("nFirst 100 numbers which are divisible by 3 and
5nn");
for (i=1; i<=100; i++)
if (i%3==0 && i%5==0)
printf("t%d", i);
getch();
14
}
Output:

15. 14. Program to Find Factorial of a Number using Recursion
#include <stdio.h>
#include<conio.h>
long fact(int);
main()
{
int n;
long f;
printf("nEnter number to find factorial: ");
scanf("%d", &n);
f = fact(n);
printf("nFactorial: %ld", f);
getch();
}
long fact(int n)
{
int m;
if (n == 1)
return n;
else
{
m = n * fact(n-1);
return m;
}
}
15

16. 15.Program to Reverse a Given Number .
#include <stdio.h>
#include<conio.h>
main()
{
long n;
int rev;
printf("nEnter any number: ");
scanf("%ld", &n);
printf("nReverse no. is:nn");
while (n > 0)
{
rev = n % 10;
n = n / 10;
printf("%d", rev);
}
getch();
}
Output:
16

17. 16. Program to Find Vowels in a String.
#include <stdio.h>
#include <string.h>
#include<conio.h>
main()
{
char str[20];
int count=0, i=0;
printf("nEnter any string: ");
gets(str);
while (str[i] != '0')
{
if (str[i]=='a' || str[i]=='e' || str[i]=='i' ||
str[i]=='o' || str[i]=='u')
count++;
i++;
}
printf("nNo. of vowels: %d", count);
getch();
}
Output:
17

18. 17. Program to add two matrices.
#include <stdio.h>
#include<conio.h>
main()
{
int a[10][10], b[10][10], c[10][10], i, j, row, col;
printf("nEnter number of rows and columns: ");
scanf("%d %d", &row, &col);
printf("nEnter elements of Array A:n");
for (i=0; i<row; i++)
for (j=0; j<col; j++)
scanf("%d", &a[i][j]);
printf("nEnter elements of Array B:n");
for (i=0; i<row; i++)
for (j=0; j<col; j++)
scanf("%d", &b[i][j]);
printf("nElements of Matrix A:nn");
for (i=0; i<row; i++)
{
for (j=0; j<col; j++)
printf("t%d", a[i][j]);
printf("nn");
}
printf("nElements of Matrix B:nn");
for (i=0; i<row; i++)
{
for (j=0; j<col; j++)
printf("t%d", b[i][j]);
printf("nn");
}
for (i=0; i<row; i++)
for (j=0; j<col; j++)
c[i][j] = a[i][j] + b[i][j];
printf("nMatrix Addition is:nn");
for (i=0; i<row; i++)
{
for (j=0; j<col; j++)
printf("t%d", c[i][j]);
printf("n");
}
getch();
}
18

19. Output:
19

20. 18. Program to Concatenate Two Strings using strcat ().
#include <stdio.h>
#include <string.h>
#include<conio.h>
main()
{
char s1[20], s2[20];
printf("nEnter first string: ");
gets(s1);
printf("nEnter second string: ");
gets(s2);
strcat(s1, s2);
printf("nThe concatenated string is: %s", s1);
getch();
}
Output:
20

21. 19. Program to Concatenate Two Strings without using strcat ().
#include <stdio.h>
#include <conio.h>
#include <string.h>
main()
{
char string1[30], string2[20];
int i, length=0, temp;
printf("Enter the Value of String1: n");
gets(string1);
printf("nEnter the Value of String2: n");
gets(string2);
for(i=0; string1[i]!='0'; i++)
length++;
temp = length;
for(i=0; string2[i]!='0'; i++)
{
string1[temp] = string2[i];
temp++;
}
string1[temp] = '0';
printf("nThe concatenated string is:n");
puts(string1);
getch();
}
Output:
21

22. 20. Program to Compare Two Strings using strcmp() .
#include <stdio.h>
#include<conio.h>
#include <string.h>
main()
{
char s1[20], s2[20];
int result;
printf("nEnter first string: ");
gets(s1);
printf("nEnter second string: ");
gets(s2);
result = strcmp(s1, s2);
if (result == 0)
printf("nBoth strings are equal");
else
printf("nBoth strings are not equal");
getch();
}
Output:
22

23. 21. Program to Compare Two Strings Without using strcmp() .
#include<stdio.h>
#include<conio.h>
main()
{
char string1[5],string2[5];
int i,temp = 0;
printf("Enter the string1 value:n");
gets(string1);
printf("nEnter the String2 value:n");
gets(string2);
for(i=0; string1[i]!='0'; i++)
{
if(string1[i] == string2[i])
temp = 1;
else
temp = 0;
}
if(temp == 1)
printf("Both strings are same.");
else
printf("Both string not same.");
getch();
}
Output:
23

24. 22. Program to Copy String using strcpy() .
#include <stdio.h>
#include<conio.h>
#include <string.h>
main()
{
char s1[20], s2[20];
printf("nEnter string into s1: ");
gets(s1);
strcpy(s2, s1);
printf("ns2: %s", s2);
getch();
}
Output:
24

25. 23. Program to Find Length of a String using strlen().
#include <stdio.h>
#include<conio.h>
#include <string.h>
main()
{
char s1[20];
int len;
printf("nEnter any string: ");
gets(s1);
len = strlen(s1);
printf("nLength of string: %d", len);
getch();
}
Output:
25

26. 24. Program to Reverse a String without using strrev() .
#include <stdio.h>
#include <conio.h>
#include <string.h>
main()
{
char string1[10], string2[10];
int i, length;
printf("Enter any string:n");
gets(string1);
length = strlen(string1)-1;
for(i=0; string1[i]!='0'; i++)
{
string2[length]=string1[i];
length--;
}
string2[length]='0';
printf("nThe Reverse of string is:n");
puts(string2);
getch();
}
Output:
26