LeetCode刷题之三：判断两个二叉树是否相同

题目为：

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.

解题思路：这种题目也是递归操作简单

代码为：

/** * Definition for binary tree * public class TreeNode { *     int val; *     TreeNode left; *     TreeNode right; *     TreeNode(int x) { val = x; } * } */public class Solution {    public boolean isSameTree(TreeNode p, TreeNode q) {        boolean flag = false;        if(p==null && q == null)            return true;        if(p == null && q!= null)            return false;        if(p!= null && q== null)            return false;        if(p.val != q.val)            return false;        return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);            }}