题目：​​原题链接​​（简单）

标签：数组、队列、滑动窗口

解法一：

class Solution:
    def maxSlidingWindow(self, nums: List[int], k: int) -> List[int]:
        if not nums:
            return []

        ans = [max(nums[:k])]
        for i in range(k, len(nums)):
            if nums[i] >= ans[-1]:
                ans.append(nums[i])
            elif nums[i - k] == ans[-1]:
                ans.append(max(nums[i - k + 1:i + 1]))
            else:
                ans.append(ans[-1])

        return ans

解法二（双向队列）：

class Solution:
    def maxSlidingWindow(self, nums: List[int], k: int) -> List[int]:
        # 处理特殊情况
        if not nums or k == 0:
            return []
        if k == 1:
            return nums

        # 初始化滑动窗口队列
        queue = collections.deque()

        max_idx = 0

        for i in range(k):
            if queue and queue[0] == i - k:
                queue.popleft()

            while queue and nums[queue[-1]] < nums[i]:
                queue.pop()

            queue.append(i)

            if nums[i] > nums[max_idx]:
                max_idx = i

        ans = [nums[max_idx]]

        # 遍历并滑动窗口
        for i in range(k, len(nums)):
            if queue and queue[0] == i - k:
                queue.popleft()

            while queue and nums[queue[-1]] < nums[i]:
                queue.pop()

            queue.append(i)

            ans.append(nums[queue[0]])

        return ans