GCD.java

/**
 * GCD.java
 * Steven Pajuelo
 * spajuelo
 * pa3
 * Make a GCD to find GCD for two integer types, which neither are negative or of another type.
 */

import java.util.Scanner;

public class GCD {


    private static int divisor, dividend, gcd;
    private static Scanner scan = new Scanner(System.in);


    public static void main(String[] args) {

        // Ask for dividend 
        System.out.print("Enter a positive integer: ");
        Boolean cont = true;

        // check type and save if int type
        checkType(scan);
        dividend = scan.nextInt();

        // compare, to discard negative numbers for dividend and divisor
        while (cont) {

            if(dividend > 0) {
                System.out.print("Enter another positive integer: ");
                checkType(scan);
                divisor = scan.nextInt();
            }
            if(dividend < 0) {
                System.out.print("Please enter a positive integer: ");
                checkType(scan);
                dividend = scan.nextInt();
            }
            if(divisor < 0) {
                System.out.print("Please enter a positive integer: ");
                checkType(scan);
                divisor = scan.nextInt();
            }
            if(divisor > 0) {
                cont = false;
            }
        }

        System.out.println("GCD of " + dividend + " and " + divisor + " is " + gcd() + ".");

    }

    // method for computer gcd
    public static int gcd() {
        while (divisor != 0) {
            int temp = divisor;
            divisor = dividend % divisor;
            dividend = temp;
            gcd = dividend;
        }
        return gcd;
    }

    // method for checking the right type (int)
    public static void checkType(Scanner scan) {
        while (true) {
            if(scan.hasNextInt()) {
                break;
            } else {
                System.out.print("Please enter a positive 'integer': ");
                scan.next();
                continue;
            }

        }


    }

}