GCD (HCF)

Find the greatest common divisor (HCF) of two numbers using Euclidean algorithm.

JavaIntermediate
Java
import java.util.Scanner;

public class Main {
    private static int gcd(int a, int b) {
        while (b != 0) {
            int temp = b;
            b = a % b;
            a = temp;
        }
        return a;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter first number: ");
        int a = sc.nextInt();
        System.out.print("Enter second number: ");
        int b = sc.nextInt();

        System.out.println("GCD = " + gcd(a, b));
        sc.close();
    }
}

Output

Enter first number: 24
Enter second number: 36
GCD = 12

We repeatedly replace (a, b) with (b, a % b) until b becomes 0.