2646. Kth Largest Sum in a Binary Tree
My accepted C++ solution to LeetCode problem 2646, Kth Largest Sum in a Binary Tree, running in 66ms.
- Difficulty: Medium
- C++
- Runtime 66ms
- Memory 271.2MB
- Updated
Read the problem on LeetCode View on GitHub
The problem statement is LeetCode’s and stays on their site. What follows is my accepted solution.
C++
Accepted on LeetCode — runtime 66ms, memory 271.2MB, accepted 2025-12-27.
class Solution {
public:
long long kthLargestLevelSum(TreeNode* root, int k) {
vector<long long> sums;
queue<TreeNode*> q;
q.push(root);
while (!q.empty()) {
int size = q.size();
long long sum = 0;
for (int i = 0; i < size; i++) {
TreeNode* node = q.front(); q.pop();
sum += node->val;
if (node->left) q.push(node->left);
if (node->right) q.push(node->right);
}
sums.push_back(sum);
}
if (k > sums.size()) return -1;
sort(sums.rbegin(), sums.rend());
return sums[k-1];
}
};