535. Encode and Decode TinyURL

class Solution {public: ???long max_id = 0; ???unordered_map<long,string> id_long; ???????// Encodes a URL to a shortened URL. ???string encode(string longUrl) { ???????id_long[max_id++] = longUrl; ???????return to_string(max_id - 1); ???} ???// Decodes a shortened URL to its original URL. ???string decode(string shortUrl) { ???????long id = stol(shortUrl); ???????return id_long[id]; ???}};// Your Solution object will be instantiated and called as such:// Solution solution;// solution.decode(solution.encode(url));