C program for GCD


 #include <stdio.h>

int gcd(int a, int b){
	if(b==0)
		return a;
	else
		return gcd(b, a%b);
}
int main(){
	
	int a, b;
	printf("Enter a and b:");
	scanf("%d %d", &a, &b);
	if(a>b){
		printf("The gcd of %d and %d is %d", a, b, gcd(a, b));	
	}else{
		printf("The gcd of %d and %d is %d", a, b, gcd(b, a));
	} 

OUTPUT: