LeetCode OJ 100. Same Tree

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.

很简单，直接上代码：

 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) return true;
13         else if(p!=null && q!=null){
14             if(isSameTree(p.left, q.left) && isSameTree(p.right, q.right)){
15                 if(p.val == q.val) return true;
16                 else return false;
17             }
18             else return false;
19         }
20         else return false;
21     }
22 }