2026-01-06 10:05:37 +0300 MSK

# 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:
        cur, nxt = [root], []
        level = 1
        min_level, max_sum = 1, root.val
        while cur or nxt:
            cur_sum = 0
            while cur:
                node = cur.pop()
                cur_sum += node.val
                if node.left:
                    nxt.append(node.left)
                if node.right:
                    nxt.append(node.right)
            if cur_sum > max_sum:
                min_level, max_sum = level, cur_sum
            cur, nxt = nxt, cur
            level += 1
        return min_level