The Java Program: 7-library-puzzlers/puzzle-59/Differences.java

  1 import java.util.*;
  2 
  3 public class Differences {
  4     public static void main(String[] args) {
  5         int vals[] = { 789, 678, 567, 456, 345, 234, 123, 012 };
  6         Set<Integer> diffs = new HashSet<Integer>();
  7 
  8         for (int i = 0; i < vals.length; i++)
  9             for (int j = i; j < vals.length; j++)
 10                 diffs.add(vals[i] - vals[j]);
 11         System.out.println(diffs.size());
 12     }
 13 }