【LeeCode】1396. 设计地铁系统(不完整)

【题目描述】

https://leetcode.cn/problems/design-underground-system/

【示例】

【题目描述】admin

import java.util.*;
// 2023-8-19

class Event {
    public int id;
    public String name;
    public int time;

    public Event(int id, String name, int time){
        this.id = id;
        this.name = name;
        this.time = time;
    }
}

class StartEnd {
    public String start;
    public String end;
    public int cost;

    public StartEnd(String start, String end, int cost){
        this.start = start;
        this.end = end;
        this.cost = cost;
    }
}

class UndergroundSystem {
    Map<Integer,Event> map;
    Map<Integer, StartEnd> timeCost;
    public UndergroundSystem() {
        map  = new HashMap<>();
        timeCost = new HashMap<>();
    }

    public void checkIn(int id, String stationName, int t) {
        Event event = new Event(id, stationName, t);
        map.put(id, event);
    }

    public void checkOut(int id, String stationName, int t) {
        Event event = map.get(id);
        timeCost.put(id, new StartEnd(event.name, stationName, t - event.time));
    }

    public double getAverageTime(String startStation, String endStation) {
        double count = 0;
        double sum = 0;
        double avage = 0.0;
        for (Map.Entry<Integer, StartEnd> x : timeCost.entrySet()) {
            StartEnd st = x.getValue();
            if (st.start.equals(startStation) && st.end.equals(endStation)){
                count++;
                sum += st.cost;
            }
        }
        avage = (double) sum / count;
        return avage;
    }
}

public class Main {
    public static void main(String[] args) {
        UndergroundSystem undergroundSystem = new UndergroundSystem();
        undergroundSystem.checkIn(45, "Leyton", 3);
        undergroundSystem.checkIn(32, "Paradise", 8);
        undergroundSystem.checkIn(27, "Leyton", 10);
        undergroundSystem.checkOut(45, "Waterloo", 15);  // 乘客 45 "Leyton" -> "Waterloo" ，用时 15-3 = 12
        undergroundSystem.checkOut(27, "Waterloo", 20);  // 乘客 27 "Leyton" -> "Waterloo" ，用时 20-10 = 10
        undergroundSystem.checkOut(32, "Cambridge", 22); // 乘客 32 "Paradise" -> "Cambridge" ，用时 22-8 = 14
        undergroundSystem.getAverageTime("Paradise", "Cambridge"); // 返回 14.00000 。只有一个 "Paradise" -> "Cambridge" 的行程，(14) / 1 = 14
        undergroundSystem.getAverageTime("Leyton", "Waterloo");    // 返回 11.00000 。有两个 "Leyton" -> "Waterloo" 的行程，(10 + 12) / 2 = 11
        undergroundSystem.checkIn(10, "Leyton", 24);
        undergroundSystem.getAverageTime("Leyton", "Waterloo");    // 返回 11.00000
        undergroundSystem.checkOut(10, "Waterloo", 38);  // 乘客 10 "Leyton" -> "Waterloo" ，用时 38-24 = 14
        undergroundSystem.getAverageTime("Leyton", "Waterloo");    // 返回 12.00000 。有三个 "Leyton" -> "Waterloo" 的行程，(10 + 12 + 14) / 3 = 12
    }
}

写在后面

    从22年12月前后开始刷leecode, 中间陆陆续续有中断、有痛苦、有放弃，到今天2023年8月19日又重新捡起, 太多的内心煎熬, 想放弃, 又想着能放弃吗？ 就真的学不会吗？ 就真的这么菜吗？ 大佬不也是从新手开始的吗？ 但不可否认的是, 这东西跟天赋有关系，跟个人的长年累月的积累也是有关系的。当然我也承认, 这东西说有用也有有用，说无用也不能否定。哎，想放弃，又想说我坚持一下再试试？算了吧，再试试