剑指Offer 45 把数组排成最小的数

把数组排成最小的数

输入一个正整数数组，把数组里所有数字拼接起来排成一个数，打印能拼接出的所有数字中最小的一个。例如输入数组{3，32，321}，则打印出这三个数字能排成的最小数字为321323。

# -*- coding:utf-8 -*-
class LargerNum(str):        
    def __lt__(x,y):
        return x+y < y+x
class Solution:
    def PrintMinNumber(self, numbers):
        if len(numbers) == 0:
            return ''
        numbers = [str(num) for num in numbers]
        numbers.sort(key = LargerNum)
        return '0' if numbers[0] == '0' else ''.join(numbers)
        # write code here

 

leetcode地址，Java版代码：

class Solution {
    public String minNumber(int[] nums) {
        int n = nums.length;
        String[] strNumStrings = new String[n];
        for (int i = 0; i < n; i++) {
            strNumStrings[i] = nums[i] + "";
        }
        Arrays.sort(strNumStrings, new Comparator<String>() {
            @Override
            public int compare(String o1, String o2) {
                Long n1 = Long.valueOf(o1.concat(o2));
                Long n2 = Long.valueOf(o2.concat(o1));
                if (n1 < n2) {
                    return -1;
                } else if (n1 >= n2) {
                    return 1;
                } else {
                    return 0;
                }
            }
        });
        StringBuilder stringBuilder = new StringBuilder();
        for (int i = 0; i < n; i++) {
            stringBuilder.append(strNumStrings[i]);
        }
        return stringBuilder.toString();
    }
}