Chapter 5 Exercise 14, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

*5.14 (Compute the greatest common divisor) Another solution for Listing 5.9 to find the greatest common divisor of two integers n1 and n2 is as follows: First find d to be the minimum of n1 and n2, then check whether d, d-1, d-2, . . . , 2, or 1 is a divisor for both n1 and n2 in this order. The first such common divisor is the greatest common divisor for n1 and n2. Write a program that prompts the user to enter two positive integers and displays the gcd.

import java.util.Scanner;
 
 
public class ProgrammingEx5_14 {
 
 public static void main(String[] args) {
  System.out.println("Enter two intergers:");
  Scanner input = new Scanner(System.in);
  int n1 = input.nextInt();
  int n2 = input.nextInt();
 
  // find the minimum
  if (n2 < n1) {
   int temp = n2;
   n2 = n1;
   n1 = temp;
  }
 
  for (int d = n1; true; d--) {
 
   if (n1 % d == 0 && n2 % d == 0) {
    System.out.println("The GCD is:" + d);
    break;
   }
 
  }
 
 }
 
}