剑指Offer(Python多种思路实现):把数组排成最小的数
面试45题:
题:把数组排成最小的数
题目: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。
解题思路一:暴力破解:先求所有数字的全排列,然后求最小值
import itertools
class Solution:
def PrintMinNumber(self, numbers):
# write code here
#暴力解法
if len(numbers)<=0:
return ""
str_numbers=[str(i) for i in numbers]
premu=itertools.permutations(str_numbers)
res=[''.join(i) for i in premu]
return min(res)
解题思路二:将数字转换为字符串后进行自定义排序
class Solution:
def PrintMinNumber(self, numbers):
# write code here
#暴力解法
if len(numbers)<=0:
return ""
str_numbers=[str(i) for i in numbers]
res=sorted(str_numbers,cmp=lambda x,y:cmp(x+y,y+x))
return ''.join(res)