平衡二叉樹[劍指offer]之python實現
阿新 • • 發佈:2019-02-07
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。
# -*- 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?