mirror of
https://github.com/halfrost/LeetCode-Go.git
synced 2025-07-05 08:27:30 +08:00
45 lines
1.9 KiB
Markdown
Executable File
45 lines
1.9 KiB
Markdown
Executable File
# [239. Sliding Window Maximum](https://leetcode.com/problems/sliding-window-maximum/)
|
||
|
||
|
||
|
||
## 题目
|
||
|
||
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
|
||
|
||
**Note:**
|
||
|
||
You may assume *k* is always valid, 1 ≤ k ≤ input array's size for non-empty array.
|
||
|
||
**Follow up:**
|
||
|
||
Could you solve it in linear time?
|
||
|
||
|
||
## 题目大意
|
||
|
||
给定一个数组 nums，有一个大小为 k 的滑动窗口从数组的最左侧移动到数组的最右侧。你只可以看到在滑动窗口 k 内的数字。滑动窗口每次只向右移动一位。返回滑动窗口最大值。
|
||
|
||
|
||
## 解题思路
|
||
|
||
- 给定一个数组和一个窗口为 K 的窗口，当窗口从数组的左边滑动到数组右边的时候，输出每次移动窗口以后，在窗口内的最大值。
|
||
- 这道题最暴力的方法就是 2 层循环，时间复杂度 O(n * K)。
|
||
- 另一种思路是用优先队列，每次窗口以后的时候都向优先队列里面新增一个节点，并删除一个节点。时间复杂度是 O(n * log n)
|
||
- 最优的解法是用双端队列，队列的一边永远都存的是窗口的最大值，队列的另外一个边存的是比最大值小的值。队列中最大值左边的所有值都出队。在保证了双端队列的一边即是最大值以后，时间复杂度是 O(n)，空间复杂度是 O(K)
|
||
|