LeetCode--Same Tree

题目：

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.

解决方案：

/** * 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) {        if(p==null&&q==null){            return true;        }else if(p==null||q==null){            return false;        }else{            return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right)&&p.val==q.val;        }            }}

ps：效率不是很高，有效率高的请在评论里留个链接或者代码，谢谢！