解题思路：

class Solution {public int[] maxSlidingWindow(int[] nums, int k) {if(nums.length == 0 || k == 0) return new int[0];Deque<Integer> deque = new LinkedList<>();int[] res = new int[nums.length - k + 1];// 未形成窗口for(int i = 0; i < k; i++) {while(!deque.isEmpty() && deque.peekLast() < nums[i])deque.removeLast();deque.addLast(nums[i]);}res[0] = deque.peekFirst();// 形成窗口后for(int i = k; i < nums.length; i++) {if(deque.peekFirst() == nums[i - k])deque.removeFirst();while(!deque.isEmpty() && deque.peekLast() < nums[i])deque.removeLast();deque.addLast(nums[i]);res[i - k + 1] = deque.peekFirst();}return res;}
}