给定两个二叉树，编写一个函数来检验它们是否相同。如果两个树在结构上相同，并且节点具有相同的值，则认为它们是相同的。示例 1:输入:       1         1/ \       / \2   3     2   3[1,2,3],   [1,2,3]输出: true### 代码```java
/*** Definition for a binary tree node.* public class TreeNode {*     int val;*     TreeNode left;*     TreeNode right;*     TreeNode() {}*     TreeNode(int val) { this.val = val; }*     TreeNode(int val, TreeNode left, TreeNode right) {*         this.val = val;*         this.left = left;*         this.right = right;*     }* }*/
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 p.val==q.val&&isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);}
}