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:
        def checkHeight(node) -> int:
            if not node:
                return 0
            leftH = checkHeight(node.left)
            rightH = checkHeight(node.right)
            if leftH == -1 or rightH == -1 or abs(leftH - rightH) > 1:
                return -1
            return max(leftH, rightH) + 1

        return checkHeight(pRoot) != -1