LeetCode: Largest Number

/**
 * Created by hzhou on 2015/5/13.
 * <p/>
 * Given a list of non negative integers, arrange them such that they form the largest number.
 * <p/>
 * For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330.
 * <p/>
 * Note: The result may be very large, so you need to return a string instead of an integer.
 * <p/>
 * http://www.programcreek.com/2014/02/leetcode-largest-number-java/
 */
public class LargestNumber {
    public String largestNumber(int[] nums) {
        if (nums == null || nums.length == 0) {
            return "";
        }
        String[] strings = new String[nums.length];
        for (int i = 0; i < nums.length; i++) {
            strings[i] = String.valueOf(nums[i]);
        }
        Arrays.sort(strings, new Comparator<String>() {
            public int compare(String o1, String o2) {
                String s1 = o1 + o2;
                String s2 = o2 + o1;
                return -1 * s1.compareTo(s2);
            }
        });
        StringBuilder sb = new StringBuilder();
        for (String s : strings) {
            sb.append(s);
        }
        String result = sb.toString();
        int i = 0;
        while (i < result.length() && result.charAt(i) == '0') {
            i++;
        }
        return i == result.length() ? "0" : result.substring(i, result.length());
    }
}