This program is to find the square of a number.

Logic:

• for even number: 4 * (n/2)^2
• for odd number: 4 * (n/2)^2 + 4 * (n/2) + 1

(n/2) = (n >> 1)

#include <stdio.h>

int square(int num)
{
    if (num ==1)
      return 1;
    else if (num ==0)
      return 0;
    else if (num%2 ==0)
      return (4 * square(num >> 1));
    else
    return (4 * square(num >>1) + 4 * (num >>1) +1);    
}

int main()
{
  int num;
  printf("\n Enter the number: ");
  scanf("%d", &num);
  printf("\n The square of the number is: %d", square(num));
  
  return 0;
}

Output:

Enter the number: 4
The square of the number is: 16

Categories: C Language