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
        if not pRoot:
            return True
        depth,is_balance = self.balance(pRoot)
        return is_balance
    
    
    def balance(self,pRoot):
        if not pRoot:
            return (0,True)
        left = self.balance(pRoot.left)
        right = self.balance(pRoot.right)
        return (1+max(left[0],right[0]),left[1] and right[1] and abs(left[0]-right[0])<=1)