LeetCode 239. Sliding Window Maximum（滑动窗口）

题目链接：点击这里

class Solution {
public:
    vector<int> maxSlidingWindow(vector<int>& nums, int k) {
        if(nums.size() < 2) return nums;
        vector<int> ans;

        deque<int> q;
        for(int i = 0; i < k; ++i)      //初始，寻找0~k-1的最大值
        {
            while(!q.empty()&&nums[q.back()]<=nums[i])
                q.pop_back();
            q.push_back(i);
        }
        ans.push_back(nums[q.front()]);

        for(int i = k; i < nums.size(); ++i)
        {
            while(!q.empty()&&q.front()<=i-k)
                q.pop_front();
            
            while(!q.empty()&&nums[q.back()]<nums[i])
                q.pop_back();
            
            q.push_back(i);

            ans.push_back(nums[q.front()]);
        }
        return ans;      
    }
};