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：

 /**
  * Definition for a binary tree node.
  * 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){
             if(isSameTree(p.left, q.left) && isSameTree(p.right, q.right)){
                 if(p.val == q.val) return true;
                 else return false;
             }
             else return false;
         }
         else return false;
     }
 }