Sliding Window Maximum
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.
For example,
Given nums = [1,3,-1,-3,5,3,6,7]
, and k = 3.
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
Therefore, return the max sliding window as [3,3,5,5,6,7]
.
Note:
You may assume k is always valid, ie: 1 ≤ k ≤ input array's size for non-empty array.
Follow up:
Could you solve it in linear time?
Analyse: Find the maximum in each window and push it into the result vector.
Runtime: 340ms.
1 class Solution { 2 public: 3 vector<int> maxSlidingWindow(vector<int>& nums, int k) { 4 vector<int> result; 5 if(nums.size() == 0) return result; 6 7 int left = 0, right = k - 1; 8 while(right < nums.size()){ 9 int temp = INT_MIN; //maximum in the current window 10 if(left == right) temp = nums[left]; 11 else{ 12 for(int i = left; i <= right; i++) 13 temp = max(temp, nums[i]); 14 } 15 result.push_back(temp); 16 left++; 17 right++; 18 } 19 return result; 20 } 21 };