/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
	bool isSameTree(TreeNode* p, TreeNode* q) {
		if (!p && !q) return true;
		if ((!p || !q) || p->val != q->val) return false;
		return isSameTree(p->left, q->left) && isSameTree(p->right, q->right);
	}
};