劍指Offer(Python多種思路實現):把數組排成最小的數
面試45題:
題:把數組排成最小的數
題目:輸入一個正整數數組,把數組裏所有數字拼接起來排成一個數,打印能拼接出的所有數字中最小的一個。例如輸入數組{3,32,321},則打印出這三個數字能排成的最小數字爲321323。
解題思路一:暴力破解:先求所有數字的全排列,然後求最小值
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)
解題思路二:將數字轉換爲字符串後進行自定義排序
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)