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