leetcode 845
作者:互联网
山峰数组指, 先严格递增, 再严格递减的数组. 现给到一个数组, 找到一个连续子数组, 使得该子数组是山峰数组, 输出最长的该子数组的长度.
要求只遍历一遍数组, 并且空间复杂度为O(1)
想了10分钟知道怎么写, 写了40分钟才debug没问题, 提交了5次前后, 我觉得我是一个sb.
class Solution:
def longestMountain(self, arr: List[int]) -> int:
result = 0
if len(arr) <= 2:
return 0
result = 0
first_index = 0
pre_num = arr[0]
left = 0
sign = 0
for i in range(1, len(arr)):
# print(f"current index: {i}, sign = {sign}, left = {left}")
current_num = arr[i]
if pre_num < current_num:
if sign == 0:
pass
else:
tmp = i - 1 - left + 1
result = max(tmp, result)
left = i - 1
sign = 0
elif pre_num == current_num:
if sign == 0:
left = i
else:
tmp = i - 1 - left + 1
result = max(tmp, result)
# print(left, i, tmp)
left = i
sign = 0
else:
if sign == 0:
if left == i - 1:
left = i
else:
sign = 1
tmp = i - left + 1
result = max(tmp, result)
# print(left, i, tmp)
else:
tmp = i - left + 1
result = max(tmp, result)
# print(left, i, tmp)
pre_num = current_num
return result
标签:山峰,845,int,arr,该子,数组,分钟,leetcode 来源: https://www.cnblogs.com/mangmangbiluo/p/15586720.html