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1116. Maximum Level Sum of a Binary Tree

My accepted Python solution to LeetCode problem 1116, Maximum Level Sum of a Binary Tree, running in 22ms.

  • Difficulty: Medium
  • Python
  • Runtime 22ms
  • Memory 21.5MB

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.

Python

Accepted on LeetCode — runtime 22ms, memory 21.5MB, accepted 2026-01-02.

python
# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def maxLevelSum(self, root: Optional[TreeNode]) -> int:
        from collections import deque
        
        if not root:
            return 0
        
        queue = deque([root])
        max_sum = float('-inf')
        result_level = 1
        level = 0
        
        while queue:
            level += 1
            level_sum = 0
            size = len(queue)
            
            for _ in range(size):
                node = queue.popleft()
                level_sum += node.val
                if node.left:
                    queue.append(node.left)
                if node.right:
                    queue.append(node.right)
            
            if level_sum > max_sum:
                max_sum = level_sum
                result_level = level
        
        return result_level

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