The code below finds highest common factor and least common multiple of two integers. HCF is also known as greatest common divisor(GCD) or greatest common factor(gcf).

### C Program

#include <stdio.h> int main() { int a, b, x, y, t, gcd, lcm; printf("Enter two integers\n"); scanf("%d%d", &x, &y); a = x; b = y; while (b != 0) { t = b; b = a % b; a = t; } gcd = a; lcm = (x*y)/gcd; printf("Greatest common divisor of %d and %d = %d\n", x, y, gcd); printf("Least common multiple of %d and %d = %d\n", x, y, lcm); return 0; }

### C program to find hcf and lcm using recursion

#include <stdio.h> long gcd(long, long); int main() { long x, y, hcf, lcm; printf("Enter two integers\n"); scanf("%ld%ld", &x, &y); hcf = gcd(x, y); lcm = (x*y)/hcf; printf("Greatest common divisor of %ld and %ld = %ld\n", x, y, hcf); printf("Least common multiple of %ld and %ld = %ld\n", x, y, lcm); return 0; } long gcd(long a, long b) { if (b == 0) { return a; } else { return gcd(b, a % b); } }