_110. Balanced Binary Tree.md

110. Balanced Binary Tree

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First completed : July 04, 2024

Last updated : July 04, 2024

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

Acceptance Rate : 54.1 %

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Solutions

• e110.py

Python

e110.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 isBalanced(self, root: Optional[TreeNode]) -> bool:
        def dfs(curr: Optional[TreeNode]) -> int :
            if not curr :
                return 0
            
            left, right = dfs(curr.left), dfs(curr.right)

            if left == -1 or right == -1 :
                return -1

            if abs(left - right) > 1 :
                return -1

            return max(left, right) + 1

        return True if dfs(root) != -1 else False