Given an array nums, there is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time the sliding window moves right by one position. Return the max sliding window.
Example:
Input: nums =[1,3,-1,-3,5,3,6,7], and k = 3 Output:[3,3,5,5,6,7] Explanation:Window position Max --------------- ----- [1 3 -1] -3 5 3 6 7 3 1 [3 -1 -3] 5 3 6 7 3 1 3 [-1 -3 5] 3 6 7 5 1 3 -1 [-3 5 3] 6 7 5 1 3 -1 -3 [5 3 6] 7 6 1 3 -1 -3 5 [3 6 7] 7
滑动窗口中的最大值，使用双端队列保存下标，窗口内左边比右边第一个小的不用考虑。
class Solution {
private Deque<Integer> deque = new ArrayDeque<>();
public int[] maxSlidingWindow(int[] nums, int k) {
if (nums == null || nums.length <= 0)
return new int[0];
int[] res = new int[nums.length - k + 1];
for (int i=0; i<nums.length; i++) {
if (!deque.isEmpty() && deque.peekFirst() == i-k)
deque.pollFirst();
while (!deque.isEmpty() && nums[deque.peekLast()] < nums[i])
deque.pollLast();
deque.offerLast(i);
if (i >= k - 1)
res[i-k+1] = nums[deque.peekFirst()];
}
return res;
}
}
Given an array nums, there is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time the sliding window moves right by one position. Return the max sliding window.
Example:
Input: nums =[1,3,-1,-3,5,3,6,7], and k = 3 Output:[3,3,5,5,6,7] Explanation:Window position Max --------------- ----- [1 3 -1] -3 5 3 6 7 3 1 [3 -1 -3] 5 3 6 7 3 1 3 [-1 -3 5] 3 6 7 5 1 3 -1 [-3 5 3] 6 7 5 1 3 -1 -3 [5 3 6] 7 6 1 3 -1 -3 5 [3 6 7] 7