Leetcode 179.最大数

最大数

给定一组非负整数，重新排列它们的顺序使之组成一个最大的整数。

示例 1:

输入: [10,2]

输出: 210

示例 2:

输入: [3,30,34,5,9]

输出: 9534330

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

class Solution {
    public String largestNumber(int[] num) {
        if(null==num||num.length<1)
            return "";
        String[] snum = new String[num.length];
        for(int i=0; i<num.length; i++)
            snum[i] = String.valueOf(num[i]);
        Comparator<String> cmp = new Comparator<String>(){
            @Override
            public int compare(String s1,String s2){
                String c1 = s1+s2;
                String c2 = s2+s1;
                return c2.compareTo(c1);
            }
        };
        Arrays.sort(snum,cmp);
        if(snum[0].charAt(0)=='0')
            return "0";
        StringBuilder ans = new StringBuilder();
        for(String each:snum)
            ans.append(each);
        return ans.toString();
    }
}