Method compare

java/0179-largest-number.java:10–14

(String s1, String s2)

        Arrays.sort(arr, new Comparator<String>() {
            @Override
            public int compare(String s1, String s2) {
                String n1 = s1 + s2, n2 = s2 + s1;
                return n2.compareTo(n1);
            }
        });

        if(arr[0].equals("0")) return "0";