C++ 100. 相同的树

class Solution {
public:
    bool check(TreeNode* p, TreeNode* q){
        if(p == NULL && q == NULL) return true;
        if(p == NULL || q == NULL) return false;
        return (p -> val == q -> val) && check(p -> left, q -> left) && check(q -> right, p -> right);

    }

    bool isSameTree(TreeNode* p, TreeNode* q) {
        return check(p, q);
    }
};