O(n^3)的解法:(垃圾解法)
# class Solution(object):
# def find132pattern(self, nums):
# """
# :type nums: List[int]
# :rtype: bool
# """
# for forwardcount in range(len(nums)):
# for lattercount in range(forwardcount+1, len(nums)):
# if nums[forwardcount] < nums[lattercount]:
# for midcount in range(lattercount+1, len(nums)):
# if nums[forwardcount] < nums[midcount] < nums[lattercount]:
# return True
# return False
O(n^2)的解法:(via:负雪明烛:leetcode)
# class Solution(object):
# def find132pattern(self, nums):
# N = len(nums)
# numsi = nums[0]
# for j in range(1, N):
# for k in range(N - 1, j, -1):
# # 从列表的两端进行维护
# if numsi < nums[k] < nums[j]:
# return True
# numsi = min(numsi, nums[j]) # 始终维护numsi的小标小于nums[j]的下标
# return False
单调栈的解法之后再进行补充