C Programs

Learn C Programming

1. c program to  display "Hello world"  on screen

//C hello world example

#include <stdio.h>
 
int main()
{
  printf("Hello world\n");
  return 0;
}

/*OUTPUT*/

/* c program to perform "addition" on 2 integer

#include<stdio.h>
 
int main()
{
   int a, b, c;
 
   printf("Enter two numbers to add\n");
   scanf("%d%d",&a,&b);
 
   c = a + b;
 
   printf("Sum of entered numbers = %d\n",c);
 
   return 0;
}
/* OUTPUT */

/* C program to check leap year */

#include <stdio.h>
 
int 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);  
 
  return 0;
}
/*OUTPUT*/












/* C program to find Factorial of a number  */ 

#include <stdio.h>
 
int main()
{
  int c, n, fact = 1;
 
  printf("Enter a number to calculate it's factorial\n");
  scanf("%d", &n);
 
  for (c = 1; c <= n; c++)
    fact = fact * c;
 
  printf("Factorial of %d = %d\n", n, fact);
 
  return 0;
}
/* OUTPUT */







 
 

/* C program to perform addition, subtraction ,multiplication ,division  */ 

#include <stdio.h>
 
int main()
{
   int first, second, add, subtract, multiply;
   float divide;
 
   printf("Enter two integers\n");
   scanf("%d%d", &first, &second);
 
   add = first + second;
   subtract = first - second;
   multiply = first * second;
   divide = first / (float)second;   //typecasting
 
   printf("Sum = %d\n",add);
   printf("Difference = %d\n",subtract);
   printf("Multiplication = %d\n",multiply);
   printf("Division = %.2f\n",divide);
 
   return 0;
}

/*C program to Find HCF(highest common factor) and LCM(least common multiple).*/ 

#include <stdio.h>
 
int main() {
  int a, b, x, y, t, gcd, lcm;
 
  printf("Enter two integers\n");
  scanf("%d%d", &x, &y);
 
  a = x;
  b = y;
 
  while (b != 0) {
    t = b;
    b = a % b;
    a = t;
  }
 
  gcd = a;
  lcm = (x*y)/gcd;
 
  printf("Greatest common divisor of %d and %d = %d\n", x, y, gcd);
  printf("Least common multiple of %d and %d = %d\n", x, y, lcm);
 
  return 0;
}

/* C program to reverse a number. */

#include <stdio.h>
 
int main()
{
   int n, reverse = 0;
 
   printf("Enter a number to reverse\n");
   scanf("%d", &n);
 
   while (n != 0)
   {
      reverse = reverse * 10;
      reverse = reverse + n%10;
      n       = n/10;
   }
 
   printf("Reverse of entered number is = %d\n", reverse);
 
   return 0;
}

/* C program to check wheather entered number is Palindrome or not. */

#include <stdio.h>
 
int main()
{
   int n, reverse = 0, temp;
 
   printf("Enter a number to check if it is a palindrome or not\n");
   scanf("%d",&n);
 
   temp = n;
 
   while( temp != 0 )
   {
      reverse = reverse * 10;
      reverse = reverse + temp%10;
      temp = temp/10;
   }
 
   if ( n == reverse )
      printf("%d is a palindrome number.\n", n);
   else
      printf("%d is not a palindrome number.\n", n);
 
   return 0;
}

/* C program to print  below pattern */ 

    *
   ***
  *****
 *******
********* 

#include <stdio.h>
 
int main()
{
   int row, c, n, temp;
 
   printf("Enter the number of rows in pyramid of stars you wish to see ");
   scanf("%d",&n);
 
   temp = n;
 
   for ( row = 1 ; row <= n ; row++ )
   {
      for ( c = 1 ; c < temp ; c++ )
         printf(" ");
 
      temp--;
 
      for ( c = 1 ; c <= 2*row - 1 ; c++ )
         printf("*");
 
      printf("\n");
   }
 
   return 0;
}

/* C program to check a number is prime or not */ 

#include<stdio.h>
 
int main()
{
   int n, i = 3, count, c;
 
   printf("Enter the number of prime numbers required\n");
   scanf("%d",&n);
 
   if ( n >= 1 )
   {
      printf("First %d prime numbers are :\n",n);
      printf("2\n");
   }
 
   for ( count = 2 ; count <= n ;  )
   {
      for ( c = 2 ; c <= i - 1 ; c++ )
      {
         if ( i%c == 0 )
            break;
      }
      if ( c == i )
      {
         printf("%d\n",i);
         count++;
      }
      i++;
   }
 
   return 0;
}

/* C program to generate  Fibonacci Series */
#include<stdio.h>
 
int main()
{
   int n, first = 0, second = 1, next, c;
 
   printf("Enter the number of terms\n");
   scanf("%d",&n);
 
   printf("First %d terms of Fibonacci series are :-\n",n);
 
   for ( c = 0 ; c < n ; c++ )
   {
      if ( c <= 1 )
         next = c;
      else
      {
         next = first + second;
         first = second;
         second = next;
      }
      printf("%d\n",next);
   }
 
   return 0;
}

/* C program on linear search */

#include <stdio.h>
 
int main()
{
   int array[100], search, c, n;
 
   printf("Enter the number of elements in array\n");
   scanf("%d",&n);
 
   printf("Enter %d integer(s)\n", n);
 
   for (c = 0; c < n; c++)
      scanf("%d", &array[c]);
 
   printf("Enter the number to search\n");
   scanf("%d", &search);
 
   for (c = 0; c < n; c++)
   {
      if (array[c] == search)     /* if required element found */
      {
         printf("%d is present at location %d.\n", search, c+1);
         break;
      }
   }
   if (c == n)
      printf("%d is not present in array.\n", search);
 
   return 0;
}

/* C program on Binary search */

#include <stdio.h>
 
int main()
{
   int c, first, last, middle, n, search, array[100];
 
   printf("Enter number of elements\n");
   scanf("%d",&n);
 
   printf("Enter %d integers\n", n);
 
   for (c = 0; c < n; c++)
      scanf("%d",&array[c]);
 
   printf("Enter value to find\n");
   scanf("%d", &search);
 
   first = 0;
   last = n - 1;
   middle = (first+last)/2;
 
   while (first <= last) {
      if (array[middle] < search)
         first = middle + 1;    
      else if (array[middle] == search) {
         printf("%d found at location %d.\n", search, middle+1);
         break;
      }
      else
         last = middle - 1;
 
      middle = (first + last)/2;
   }
   if (first > last)
      printf("Not found! %d is not present in the list.\n", search);
 
   return 0;   
}

/* C program to reverse array list */

#include <stdio.h>
 
int main()
{
   int n, c, d, a[100], b[100];
 
   printf("Enter the number of elements in array\n");
   scanf("%d", &n);
 
   printf("Enter the array elements\n");
 
   for (c = 0; c < n ; c++)
      scanf("%d", &a[c]);
 
   /*
    * Copying elements into array b starting from end of array a
    */
 
   for (c = n - 1, d = 0; c >= 0; c--, d++)
      b[d] = a[c];
 
   /*
    * Copying reversed array into original.
    * Here we are modifying original array, this is optional.
    */
 
   for (c = 0; c < n; c++)
      a[c] = b[c];
 
   printf("Reverse array is\n");
 
   for (c = 0; c < n; c++)
      printf("%d\n", a[c]);
 
   return 0;
}

/* C program to sort a list using bubble sort */

 
#include <stdio.h>
 
int main()
{
  int array[100], n, c, d, swap;
 
  printf("Enter number of elements\n");
  scanf("%d", &n);
 
  printf("Enter %d integers\n", n);
 
  for (c = 0; c < n; c++)
    scanf("%d", &array[c]);
 
  for (c = 0 ; c < ( n - 1 ); c++)
  {
    for (d = 0 ; d < n - c - 1; d++)
    {
      if (array[d] > array[d+1]) /* For decreasing order use < */
      {
        swap       = array[d];
        array[d]   = array[d+1];
        array[d+1] = swap;
      }
    }
  }
 
  printf("Sorted list in ascending order:\n");
 
  for ( c = 0 ; c < n ; c++ )
     printf("%d\n", array[c]);
 
  return 0;
}

/* C Program on  insertion sort ascending order */
 
#include <stdio.h>
 
int main()
{
  int n, array[1000], c, d, t;
 
  printf("Enter number of elements\n");
  scanf("%d", &n);
 
  printf("Enter %d integers\n", n);
 
  for (c = 0; c < n; c++) {
    scanf("%d", &array[c]);
  }
 
  for (c = 1 ; c <= n - 1; c++) {
    d = c;
 
    while ( d > 0 && array[d] < array[d-1]) {
      t          = array[d];
      array[d]   = array[d-1];
      array[d-1] = t;
 
      d--;
    }
  }
 
  printf("Sorted list in ascending order:\n");
 
  for (c = 0; c <= n - 1; c++) {
    printf("%d\n", array[c]);
  }
 
  return 0;
}

/*C program to sort a list of number using selection sort */

#include <stdio.h>
 
int main()
{
   int array[100], n, c, d, position, swap;
 
   printf("Enter number of elements\n");
   scanf("%d", &n);
 
   printf("Enter %d integers\n", n);
 
   for ( c = 0 ; c < n ; c++ )
      scanf("%d", &array[c]);
 
   for ( c = 0 ; c < ( n - 1 ) ; c++ )
   {
      position = c;
 
      for ( d = c + 1 ; d < n ; d++ )
      {
         if ( array[position] > array[d] )
            position = d;
      }
      if ( position != c )
      {
         swap = array[c];
         array[c] = array[position];
         array[position] = swap;
      }
   }
 
   printf("Sorted list in ascending order:\n");
 
   for ( c = 0 ; c < n ; c++ )
      printf("%d\n", array[c]);
 
   return 0;
}

/* C program to add  two matrix */

First Matrix :-

1 2

3 4

Second matrix :-

4 5

-1 5

then output of the program (sum of First and Second matrix) will be

5 7

2 9

#include <stdio.h>
 
int main()
{
   int m, n, c, d, first[10][10], second[10][10], sum[10][10];
 
   printf("Enter the number of rows and columns of matrix\n");
   scanf("%d%d", &m, &n);
   printf("Enter the elements of first matrix\n");
 
   for (c = 0; c < m; c++)
      for (d = 0; d < n; d++)
         scanf("%d", &first[c][d]);
 
   printf("Enter the elements of second matrix\n");
 
   for (c = 0; c < m; c++)
      for (d = 0 ; d < n; d++)
            scanf("%d", &second[c][d]);
 
   printf("Sum of entered matrices:-\n");
 
   for (c = 0; c < m; c++) {
      for (d = 0 ; d < n; d++) {
         sum[c][d] = first[c][d] + second[c][d];
         printf("%d\t", sum[c][d]);
      }
      printf("\n");
   }
 
   return 0;
}