# 100 - Same Tree

解法ㄧ - Recursion

這題應該算是用 recursion 的基礎簡單題，實作如下：

/**
 * 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 == NULL && q == NULL) return true;
        if(p == NULL || q == NULL) return false;

        return (p->val == q->val) && isSameTree(p->left, q->left) && isSameTree(p->right, q->right);
    }
};