leetcode-179-最大数

题目描述：

方法一：

class LargerNumKey(str): 
    def __lt__(x, y): 
        return x+y > y+x 
class Solution: 
    def largestNumber(self, nums): 
        largest_num = ''.join(sorted(map(str, nums), key=LargerNumKey)) 
        return '0' if largest_num[0] == '0' else largest_num