100Same Tree

/**
 * 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;
if((p==null&&q!=null)||(p!=null&&q==null)) return false;
if(p.val!=q.val){
return false;
}
return isSameTree(p.left, q.left)&&isSameTree(p.right, q.right);
}


}