C Program to Find G.C.D Using Recursion

* The GCD (Greatest Common Divisor) of two positive integers entered by the user using recursion.

* This program takes two positive integers as input from the user and calculates GCD using recursion.

GCD of Two Numbers using Recursion :

Program :

#include <stdio.h>
int hcf(int n1, int n2);
int main() {
    int n1, n2;
    printf("Enter two positive integers: ");
    scanf("%d %d", &n1, &n2);
    printf("G.C.D of %d and %d is %d.", n1, n2, hcf(n1, n2));
    return 0;
}

int hcf(int n1, int n2) {
    if (n2 != 0)
        return hcf(n2, n1 % n2);
    else
        return n1;
}

Output :

Enter two positive integers: 5
158
G.C.D of 5 and 158 is 1.