递归与二叉树_leetcode110

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution(object):
    def isBalanced(self, root):
        """
        :type root: TreeNode
        :rtype: bool
        """

        if not root:
            return True



        isLB = self.isBalanced(root.left)
        isRB = self.isBalanced(root.right)

        if isLB and isRB:
            leftHeight = self.geiHeight(root.left)
            rightHeight = self.geiHeight(root.right)

            if abs(leftHeight -rightHeight) <= 1:
                return True
        return False



    def geiHeight(self,root):


        if not root:
            return 0

        return max(self.geiHeight(root.left),self.geiHeight(root.right))+1