1class Solution {2    public int[] maxSlidingWindow(int[] nums, int k) {3        Deque<Integer> deque = new ArrayDeque<>();4        int[] ans = new int[nums.length - k + 1];5        for (int i = 0; i < nums.length; i++) {6            while (!deque.isEmpty() && deque.peekFirst() <= i - k) deque.removeFirst();7            while (!deque.isEmpty() && nums[deque.peekLast()] <= nums[i]) deque.removeLast();8            deque.addLast(i);9            if (i >= k - 1) ans[i - k + 1] = nums[deque.peekFirst()];10        }11        return ans;12    }13}