leetcode

0 class Solution {

1 public:

2 int constrainedSubsetSum(vector<int> &nums, int k) {

3 deque<int> q;

4 int res = nums[0];

5 for (int i = 0; i < nums.size(); ++i) {

6 nums[i] += !q.empty() ? q.front() : 0;

7 res = max(res, nums[i]);

8 while (!q.empty() && nums[i] > q.back())

9 q.pop_back();

10 if (nums[i] > 0) q.push_back(nums[i]);

11 if (i >= k && !q.empty() && q.front() == nums[i - k]) q.pop_front();

12 }

13 return res;

14 }

15 };