解析

class Solution {
public:
  vector<int> maxSlidingWindow(vector<int> &nums, int k) {
    int n = nums.size();
    vector<int> res;
    deque<int> dp;
    for (int i = 0; i < n; i++) {
      if (!dp.empty() && dp.front() < i - k + 1) {
        dp.pop_front();
      }

      while (!dp.empty() && nums[dp.back()] < nums[i]) {
        dp.pop_back();
      }
      dp.push_back(i);

      if(i>=k-1){
        res.push_back(nums[dp.front()]);
      }
    }

    return res;
  }
};