1797. Design Authentication Manager

這題就比較單純了, 就是用一個hashmap去做紀錄

class AuthenticationManager {
public:
    AuthenticationManager(int timeToLive) {
        t2l = timeToLive;
    }
    
    void generate(string tokenId, int currentTime) {
        m[tokenId] = currentTime + t2l;
    }
    
    void renew(string tokenId, int currentTime) {
        if(!m.count(tokenId)){
            return;
        }else{
            if(m[tokenId] <= currentTime){
                return;
            }else{
                m[tokenId] = currentTime + t2l;
            }
        }
    }
    
    int countUnexpiredTokens(int currentTime) {
        int res = 0;
        for(auto i:m){
            if(i.second > currentTime){
                res++;
            }
        }
        return res;
    }
    private:
        unordered_map<string, int> m;
        int t2l;
};