给出一组非负整数,重新排序组成最大的数

例
给出 [1, 20, 23, 4, 8]，返回组合最大的整数应为 8423201
给出 [1, 201, 20, 9, 8]，返回组合最大的整数应为 98202011
给出 [1, 203, 20, 9, 8]，返回组合最大的整数应为 98203201

# Python2

class Solution:
    def largestNumber(self, nums):
        scmp = lambda a,b: int(b+a)-int(a+b)
        res = ''.join(sorted(map(str, nums), cmp=scmp)).lstrip('0')
        return res or '0'

# Python3 

from functools import cmp_to_key
class Solution:
    def largestNumber(self, nums):
        key = cmp_to_key(lambda a,b: int(b+a)-int(a+b))
        res = ''.join(sorted(map(str, nums), key=key)).lstrip('0')
        return res or '0'

# Python2 

class Solution:
    def largestNumber(self,nums):
        def cxx(x,y):
    		i = 0 
    		sx= str(x)
    		sy= str(y)
    		while i< len(str(min(x,y))):
    			if sx[i] > sy[i]:
    				return 1
    			elif sx[i] < sy[i]:
    				return -1
    			elif x == y:
    			    return 0
    			i+=1
    		if i == len(sx):
    			return -1 if sy[i]>sy[0] else 1
    		if i == len(sy):
    			return 1 if sx[i]>sx[0] else -1
    	nx = sorted(nums,cmp=lambda x,y:cxx(x,y),reverse=True)        
    	res = ''.join(map(str, nx)).lstrip('0')
    	return res or '0'     

t = Solution()
print(t.largestNumber([1, 20, 23, 4, 8]))
// 8423201