题解 | 判断是不是平衡二叉树

# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param pRoot TreeNode类 
# @return bool布尔型
#
class Solution:
    def IsBalanced_Solution(self , pRoot: TreeNode) -> bool:
        # write code here
        def height(node):
            if not node:
                return 0
            left_height = height(node.left)
            right_height = height(node.right)
            if left_height == -1 or right_height == -1 or abs(left_height - right_height) > 1:
                return -1
            return max(left_height, right_height) + 1
        
        return height(pRoot) != -1