_1161. Maximum Level Sum of a Binary Tree.md

1161. Maximum Level Sum of a Binary Tree

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First completed : July 17, 2024

Last updated : July 17, 2024

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Related Topics : Tree, Depth-First Search, Breadth-First Search, Binary Tree

Acceptance Rate : 67.16 %

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Solutions

• m1161.py

Python

m1161.py

# 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:
        lvls = defaultdict(int)

        def dfs(curr: Optional[TreeNode], lvls: defaultdict, lvl: int = 1) -> None :
            if not curr :
                return
            
            lvls[lvl] += curr.val

            dfs(curr.left, lvls, lvl + 1)
            dfs(curr.right, lvls, lvl + 1)

        dfs(root, lvls)
        return max(lvls.keys(), key=lambda x: lvls[x])