leetcode

0 class Solution {

1 public:

2 long long kthLargestLevelSum(const TreeNode *root, int k) const {

3 priority_queue<long long, vector<long long>, greater<>> pq;

4 queue<const TreeNode *> q;

5

6 for (q.emplace(root); !q.empty();) {

7 long long sum = 0;

8 for (int k = size(q); k > 0; k--) {

9 const auto root = q.front();

10 q.pop();

11 sum += root->val;

12

13 if (root->left) q.push(root->left);

14 if (root->right) q.push(root->right);

15 }

16

17 pq.emplace(sum);

18 if (size(pq) > k) pq.pop();

19 }

20

21 return size(pq) == k ? pq.top() : -1;

22 }

23 };