题目
Given an array of 4 digits, return the largest 24 hour time that can be made.
The smallest 24 hour time is 00:00, and the largest is 23:59. Starting from 00:00, a time is larger if more time has elapsed since midnight.
Return the answer as a string of length 5. If no valid time can be made, return an empty string.
解题思路
枚举四个数的排列，找到符合条件的最大时间
代码
class Solution:
def largestTimeFromDigits(self, A: List[int]) -> str:
res = -1
for h1, h2, m1, m2 in itertools.permutations(A):
hour = h1 * 10 + h2
minute = m1 * 10 + m2
if hour < 24 and minute < 60:
time = hour * 60 + minute
res = max(res, time)
return "%02d:%02d" % divmod(res, 60) if res >= 0 else ""
