package ch04_prj4_CommonDivisorCalculator;

import java.util.Scanner;

public class CommonDivisorCalculatorApp {

    public static void main(String[] args) {
        // welcome
        System.out.println("Welcome to Greatest Common Divisor Finder\n");

        // scanner
        Scanner sc = new Scanner(System.in);

        // define variable
        String moreCalcs = "y";

        // loop
        while (moreCalcs.equalsIgnoreCase("y")) {
            System.out.println("Enter first number: ");
            int first = sc.nextInt();

            System.out.println("Enter second number: ");
            int second = sc.nextInt();

            // do biz for greatest common divisor
            // Subtract x from y repeatedly until y < x.
            // 2. Swap the values of x and y.
            // 3. Repeat steps 1 and 2 until x = 0.
            // 4. y is the greatest common divisor of the two numbers.
            while (first != 0) {
                int origSecond = second;
                second = first;
                first = origSecond;

                while (second >= first) {
                    second -= first;
                }
                // print greatest common divisor
                System.out.println("Greatest common divisor: " + second + "\n");

                // continue?
                System.out.println("Continue? (y/n): ");
                moreCalcs = sc.next();
            }

        }
        System.out.println("Good bye!\n");
        sc.close();
    }
}