Problem: Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

Solution: Same Tree, Python:

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#!/usr/bin/env python
# -*- encoding: utf-8 -*-
# @Date : 2015-01-01 23:50:41
# @Author : NSSimacer
# @Version : 1.0
# Definition for a binary tree node
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
# @param p, a tree node
# @param q, a tree node
# @return a boolean
def isSameTree(self, p, q):
if p is None and q is None:
return True
if p is None or q is None:
return False
if p.val != q.val:
return False
return Solution().isSameTree(p.left, q.left) and\
Solution().isSameTree(p.right, q.right)

深搜,递归求解。