C program to find HCF (GCD) of two numbers

Example

Input

Input first number: 12
Input second number: 30

Output

HCF of 12 and 30: 6

HCF (Highest Common Factor) is the greatest number that divides exactly two or more numbers. HCF is also known as GCD (Greatest Common Divisor) or GCF (Greatest Common Factor).

/**
 * C program to find HCF of two numbers
 */

#include <stdio.h>

int main()
{
    int i, num1, num2, min, hcf=1;

    /* Input two numbers from user */
    printf("Enter any two numbers to find HCF: ");
    scanf("%d%d", &num1, &num2);

    /* Find minimum between two numbers */
    min = (num1<num2) ? num1 : num2;

    for(i=1; i<=min; i++)
    {
        /* If i is factor of both number */
        if(num1%i==0 && num2%i==0)
        {
            hcf = i;
        }
    }

    printf("HCF of %d and %d = %d\n", num1, num2, hcf);

    return 0;
}

/*
Output :

Enter any two numbers to find HCF: 12
30
HCF of 12 and 30 = 6
*/