balanced-binary-tree.py

# coding: utf-8

class Solution:
 """
 @param root: The root of binary tree.
 @return: True if this Binary tree is Balanced, or false.
 """
 def isBalanced(self, root):
 # write your code here
 if not root:
 return True
 else:
 if abs(self._isBalanced(root.left) - self._isBalanced(root.right)) <= 1:
 return self.isBalanced(root.left) and self.isBalanced(root.right)
 else:
 return False

 def _isBalanced(self, root):
 if not root:
 return 0
 return 1 + max(self._isBalanced(root.left), self._isBalanced(root.right))

# easy: http://lintcode.com/zh-cn/problem/balanced-binary-tree/