[Leetcode][python]Balanced Binary Tree/平衡二叉树

class Solution(object):
    def maxDepth(self, root):
        if root == None:
            return 0
        return max(self.maxDepth(root.left), self.maxDepth(root.right))+1

    def isBalanced(self, root):
        """
        :type root: TreeNode
        :rtype: bool
        """
        if root == None:
            return True
        if abs(self.maxDepth(root.left) - self.maxDepth(root.right)) > 1:
            return False
        return self.isBalanced(root.left) and self.isBalanced(root.right)