Sliding Window Maximum Problem
Description
LeetCode Problem 239.
You are given an array of integersnums, 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 1:
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Input: nums = [1,3,-1,-3,5,3,6,7], 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
Example 2:
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Input: nums = [1], k = 1
Output: [1]
Example 3:
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Input: nums = [1,-1], k = 1
Output: [1,-1]
Example 4:
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Input: nums = [9,11], k = 2
Output: [11]
Example 5:
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Input: nums = [4,-2], k = 2
Output: [4]
Constraints:
- 1 <= nums.length <= 10^5
- -10^4 <= nums[i] <= 10^4
- 1 <= k <= nums.length
Sample C++ Code
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class Solution {
public:
vector<int> maxSlidingWindow(vector<int>& nums, int k) {
int len = nums.size();
vector<int> ans;
deque<int> maxs;
for (int i = 0; i < len; i ++) {
while (!maxs.empty() && maxs.back() < nums[i]) maxs.pop_back();
maxs.push_back(nums[i]);
if (i >= k && nums[i-k] == maxs.front())
maxs.pop_front();
if (i >= k - 1)
ans.push_back(maxs.front());
}
return ans;
}
};