leetcode-algorithms/python/balanced_binary_tree.py at master · anishLearnsToCode/leetcode-algorithms · GitHub

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# 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 _is_balanced(self, root: TreeNode) -> int:

if root is None:

return 0

left_height = self._is_balanced(root.left)

right_height = self._is_balanced(root.right)

if left_height == -1 or right_height == -1 or abs(left_height - right_height) > 1:

return -1

return 1 + max(left_height, right_height)

def isBalanced(self, root: TreeNode) -> bool:

if root is None:

return True

return self._is_balanced(root) is not -1

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