Leetcode 239. 滑动窗口最大值

from collections import deque
class Solution(object):
    def maxSlidingWindow(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: List[int]
        """
        n=len(nums)
        res=[None]*(n-k+1)
        q=deque()
        for i in range(n):
            start=i-k+1
            while q and i-q[0]>=k:
                q.popleft()
            while q and nums[q[-1]]<=nums[i]:
                q.pop()
            q.append(i)
            if start>=0:
                res[start]=nums[q[0]]
        return res