变长滑动窗口

class Solution {
public:
    vector<int> maxInWindows(vector<int>& nums, int k) {
        int len = nums.size();
        int* q = new int[len*2];
        int head = 0, tail = 0;
        vector<int> ans;
        for(int i = 0; i < len; i ++){
            while(head < tail && q[head] < i - k + 1)head ++;
            while(head < tail && nums[i] >= nums[q[tail-1]])tail --;
            q[tail++] = i;
            if(i - k + 1 >= 0)ans.push_back(nums[q[head]]);
        }
        delete[] q;

        return ans;
    }
};