# C program to find GCD of two numbers

This is a C program to find GCD of two numbers.

The Greatest Common Divisor (GCD) or Highest Common Factor (HCF) of a given integer is the highest positive integer that divides the given integer without remainder.

For better understanding, the concept of following c programming topics is required

## C program to find GCD of two numbers using for loop

``````#include <stdio.h>

int main()
{
int x, y, i, gcd;

printf("Enter two integer values: \n");
scanf("%d %d", &x, &y);

for (i = 1; i <= x && i <= y; i++)\
{
if (x % i == 0 && y % i == 0)
gcd = i;
}

printf("GCD of %d and %d is: %d", x, y, gcd);

return 0;
}
``````

Output Explanation

The program logic to calculate GCD or HCF is simple. `fo`r loop continue till the value of `i` is equal to `x` or `y` and `if` condition checks whether the remainder of `x` and `y` when divided by `i` is equal to 0 or not.

## C program to find GCD of two numbers using while loop

``````#include <stdio.h>

int main()
{
int x, y, temp, gcd;

printf("Enter two integer: \n");
scanf("%d %d", &x, &y);

while (y != 0)
{
temp = y;
y = x % y;
x = temp;
}

gcd = x;
printf("GCD of given integers is: %d", gcd);

return 0;
}
``````

Output 