leetcode

0 class UndergroundSystem {

1 unordered_map<int, pair<string, int>> check_in;

2 unordered_map<string, pair<int, int>> average;

3

4 public:

5 UndergroundSystem() {}

6

7 void checkIn(int id, const string &stationName, int t) { check_in[id] = {stationName, t}; }

8

9 void checkOut(int id, const string &stationName, int t) {

10 auto &[name, time] = check_in[id];

11 auto &p = average[name + "-" + stationName];

12 p.second += t - time;

13 p.first++;

14 }

15

16 double getAverageTime(const string &startStation, const string &endStation) {

17 auto &p = average[startStation + "-" + endStation];

18 return (double)p.second / p.first;

19 }

20 };