Description
Given two binary trees, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical and the nodes have the same value.
Example 1:
Input: 1 1 / \ / \ 2 3 2 3 [1,2,3], [1,2,3] Output: true
Example 2:
Input: 1 1 / \ 2 2 [1,2], [1,null,2] Output: false
Example 3:
Input: 1 1 / \ / \ 2 1 1 2 [1,2,1], [1,1,2] Output: false
描述
- 此题目是给定两棵树，判断两个树是否相等.
- 两颗树相等意味着结构，值要完全一样.
- 此题目使用递归求解.
# -*- coding: utf-8 -*- # @Author: 何睿 # @Create Date: 2018-12-28 19:06:08 # @Last Modified by: 何睿 # @Last Modified time: 2018-12-28 19:12:16 class TreeNode: def __init__(self, x): self.val = x self.left = None self.right = None class Solution: def isSameTree(self, p, q): """ :type p: TreeNode :type q: TreeNode :rtype: bool """ # 如果第一个树和第二个树都是空，说明两个树是相等的，返回True. if not p and not q: return True # 如果有一个数为空另一个树不为空，说明两个树一定不会相等 if not p or not q: return False # 如果两个树的节点值不相等，则两条树不会相等，返回False if p.val != q.val: return False # 如果以上条件都通过了，说明两个树的当前节点相等 # 我们分别判断这两条树的左子树是否相等，右子树是否相等 left = self.isSameTree(p.left,q.left) right = self.isSameTree(p.right,q.right) # 返回最终结果 return left and right
源代码文件在这里.
