Design Underground System

描述

TODO

分析

TODO

代码

Python

# Design Underground System
class UndergroundSystem:

    def __init__(self):
        self.checkin_dict = {}
        self.travel_time = collections.defaultdict(int)
        self.travel_cnt = collections.defaultdict(int)
        

    def checkIn(self, id: int, stationName: str, t: int) -> None:
        self.checkin_dict[id] = (stationName,t)

    def checkOut(self, id: int, stationName: str, t: int) -> None:
        startStation,start_t = self.checkin_dict[id]
        self.travel_time[(startStation,stationName)] += t - start_t
        self.travel_cnt[(startStation,stationName)] += 1
        

    def getAverageTime(self, startStation: str, endStation: str) -> float:
        return self.travel_time[(startStation,endStation)]/self.travel_cnt[(startStation,endStation)]

Java

// TODO

C++

// TODO