179. Largest Number

Given a list of non negative integers, arrange them such that they form the largest number.

For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330.

Note: The result may be very large, so you need to return a string instead of an integer.

Credits:
Special thanks to @ts for adding this problem and creating all test cases.

程序如下所示：

class Solution {
    public String largestNumber(int[] nums) {
        int len = nums.length;
        if (len == 0){
            return "0";
        }
        String[] s = new String[len];
        for (int i = 0; i < len; ++ i){
            s[i] = String.valueOf(nums[i]);
        }
        Arrays.sort(s, new Comparator(){
            @Override
            public int compare(String s0, String s1){
                String ss0 = s0 + s1;
                String ss1 = s1 + s0;
                return ss1.compareTo(ss0);
            }
        });
        if (s[0].equals("0")){
            return "0";
        }
        StringBuilder sb = new StringBuilder();
        for (String val : s){
            sb.append(val);
        }
        return sb.toString();
    }
}