題目描述

輸入一棵二叉樹，判斷該二叉樹是否是平衡二叉樹。

題目連結

# -*- coding:utf-8 -*-
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
class Solution:
    def getDepth(self , Root):
        if Root == None:
            return 0;
        lDepth = self.getDepth(Root.left);
        rDepth = self.getDepth(Root.right);
        return
 
 max(lDepth , rDepth) + 1;

    def IsBalanced_Solution(self, pRoot):
        if not pRoot:
            return True
        lDepth = self.getDepth(pRoot.left);
        rDepth = self.getDepth(pRoot.right);
        diff = lDepth - rDepth;
        if diff < -1 or diff > 1:
            return False
 
;
        return self.IsBalanced_Solution(pRoot.left) and self.IsBalanced_Solution(pRoot.right);

求解：為什麼用val不可以記錄樹的高度？