/**

 * 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 p=q;

        return(p.val==q.val && isSameTree(p.left,q.left) && isSameTree(p.right,q.right));

    }

}