LeetCode 100

 1 /**
 2  * Definition for a binary tree node.
 3  * public class TreeNode {
 4  *     int val;
 5  *     TreeNode left;
 6  *     TreeNode right;
 7  *     TreeNode(int x) { val = x; }
 8  * }
 9  */
10 public class Solution {
11     public boolean isSameTree(TreeNode p, TreeNode q) {
12         if(p==null || q==null){
13             return p==null && q==null;
14         }else{
15             return p.val==q.val && isSameTree(p.left,q.left) && isSameTree(p.right,q.right);
16         }
17     }
18 }