Solution of Challenge - 9

A lot of people have rightly pointed out that this problem can be solved using a lexical comparison of strings. However, that's not all you need.

Consider the following example: [5, 50, 56]. A lexical comparison returns 56, 50, and 5, but that doesn't make the larger number (56, 5, 50 does)

import java.util.Arrays;
import java.util.Comparator;

public class Problem9 {
     private static Integer[] VALUES = {5, 2, 1, 9, 50, 56};
     public static void main(String[] args) {
        Arrays.sort(VALUES, new Comparator() {

            public int compare(Integer lhs, Integer rhs) {
                String v1 = lhs.toString();
                String v2 = rhs.toString();

                return (v1 + v2).compareTo(v2 + v1) * -1;
            }
            @Override
            public int compare(Object o1, Object o2) {
                throw new UnsupportedOperationException("Not supported yet.");  
                //To change body of generated methods, choose Tools | Templates.
            }
        });

        String result = "";
        for (Integer integer : VALUES) {
            result += integer.toString();
        }
        System.out.println(result);
    }
}