停车场管理系统
开发
以下为停车场管理系统的代码：
首先定义Car类，记录车辆信息：
```java
public class Car {
private String plateNumber; // 车牌号
private long enterTime; // 进入停车场时间
private long exitTime; // 离开停车场时间
public Car(String plateNumber, long enterTime) {
this.plateNumber = plateNumber;
this.enterTime = enterTime;
}
public String getPlateNumber() {
return plateNumber;
}
public long getEnterTime() {
return enterTime;
}
public long getExitTime() {
return exitTime;
}
public void setExitTime(long exitTime) {
this.exitTime = exitTime;
}
}
```
定义一个接口，包含小型车库的基本操作：
```java
public interface CarGarage {
boolean isFull(); // 是否已满
void addCar(Car car); // 将车辆加入车库
Car removeCar(String plateNumber); // 将车辆从车库中移除
boolean contains(String plateNumber); // 判断车库中是否包含指定车辆
int getSize(); // 返回车库当前的车辆数量
}
```
实现CarGarage接口，使用散列表(Node)进行模拟：
```java
public class CarGarageImpl implements CarGarage {
private static final int GARAGE_CAPACITY = 5; // 小型车库的容量
private Map
// 散列表节点类
private class Node {
Car car;
Node next;
Node(Car car, Node next) {
this.car = car;
this.next = next;
}
}
// 获取指定车辆应该存储的散列表下标
private int getIndex(String plateNumber) {
return Math.abs(plateNumber.hashCode()) % GARAGE_CAPACITY;
}
@Override
public boolean isFull() {
int size = 0;
for (Node node : garageMap.values()) {
for (; node != null; node = node.next) {
size++;
}
}
return size == GARAGE_CAPACITY;
}
@Override
public void addCar(Car car) {
int index = getIndex(car.getPlateNumber());
Node node = garageMap.get(index);
garageMap.put(index, new Node(car, node));
}
@Override
public Car removeCar(String plateNumber) {
int index = getIndex(plateNumber);
Node node = garageMap.get(index);
Node prev = null;
while (node != null) {
if (node.car.getPlateNumber().equals(plateNumber)) {
if (prev == null) {
garageMap.put(index, node.next);
} else {
prev.next = node.next;
}
return node.car;
}
prev = node;
node = node.next;
}
return null;
}
@Override
public boolean contains(String plateNumber) {
int index = getIndex(plateNumber);
Node node = garageMap.get(index);
while (node != null) {
if (node.car.getPlateNumber().equals(plateNumber)) {
return true;
}
node = node.next;
}
return false;
}
@Override
public int getSize() {
int size = 0;
for (Node node : garageMap.values()) {
for (; node != null; node = node.next) {
size++;
}
}
return size;
}
}
```
定义一个接口，包含停车场的基本操作：
```java
public interface ParkingLot {
void enter(Car car); // 车辆进场
void exit(Car car); // 车辆出场
int getEmptySpotCount(); // 返回停车场空余车位数量
}
```
实现ParkingLot接口，使用队列存储车辆排队的情况，每五个车位使用一个小型车库进行模拟：
```java
public class ParkingLotImpl implements ParkingLot {
private static final int PARKING_LOT_CAPACITY = 100; // 停车场容量
private static final int GARAGE_COUNT = PARKING_LOT_CAPACITY / 5; // 小型车库数量
private static final double PRICE_PER_15_MINUTE = 0.5; // 普通车辆停车价格：0.5元/15分钟
private static final double NIGHT_PRICE_PER_HOUR = 1; // 夜间车辆停车价格：1元/小时
private static final long NIGHT_START_TIME = 22 * 3600 * 1000; // 夜间计费开始时间：22点
private static final long NIGHT_END_TIME = 6 * 3600 * 1000; // 夜间计费结束时间：6点
private int emptySpotCount = PARKING_LOT_CAPACITY; // 停车场空余车位数量
private Queue
private Queue
private CarGarage[] garages; // 小型车库数组
public ParkingLotImpl(int entranceCount) {
entranceQueues = new Queue[entranceCount];
for (int i = 0; i < entranceCount; i++) {
entranceQueues[i] = new LinkedList<>();
}
garages = new CarGarage[GARAGE_COUNT];
for (int i = 0; i < garages.length; i++) {
garages[i] = new CarGarageImpl();
}
}
@Override
public void enter(Car car) {
int emptyGarageIndex = -1;
for (int i = 0; i < garages.length; i++) {
if (!garages[i].isFull()) {
emptyGarageIndex = i;
break;
}
}
if (emptyGarageIndex != -1) {
garages[emptyGarageIndex].addCar(car);
emptySpotCount--;
} else {
entranceQueues[0].offer(car); // 第一个入口就放排队
}
}
private long getParkingTime(Car car) {
return car.getExitTime() - car.getEnterTime();
}
private double calcPrice(long parkingTime) {
if (parkingTime <= 15 * 60 * 1000) { // 普通车免费15分钟
return 0;
} else {
double price = Math.ceil((double) parkingTime / (15 * 60 * 1000)) * PRICE_PER_15_MINUTE;
// 夜间停车价格
if (car.getEnterTime() < NIGHT_END_TIME || car.getEnterTime() >= NIGHT_START_TIME) {
price += (double) Math.ceil((double) parkingTime / (60 * 60 * 1000)) * NIGHT_PRICE_PER_HOUR;
}
return price;
}
}
@Override
public void exit(Car car) {
int garageIndex = -1;
for (int i = 0; i < garages.length; i++) {
if (garages[i].contains(car.getPlateNumber())) {
garageIndex = i;
break;
}
}
if (garageIndex != -1) {
Car removedCar = garages[garageIndex].removeCar(car.getPlateNumber());
long parkingTime = removedCar.getExitTime() - removedCar.getEnterTime();
double price = calcPrice(parkingTime);
emptySpotCount++;
System.out.println("离开了停车库，车牌号为" + removedCar.getPlateNumber() + "，停车时间为" + parkingTime +
"毫秒，需支付" + price + "元");
} else {
System.out.println("未找到车牌号为" + car.getPlateNumber() + "的车辆");
}
}
@Override
public int getEmptySpotCount() {
return emptySpotCount;
}
// 模拟车辆进场
public void simulateCarEnter() {
for (Queue
if (entranceQueue.isEmpty()) {
continue;
}
// 先检查是否有空车位，有的话直接入车库
int emptyGarageIndex = -1;
for (int i = 0; i < garages.length; i++) {
if (!garages[i].isFull()) {
emptyGarageIndex = i;
break;
}
}
// 没有空车位
if (emptyGarageIndex == -1) {
Car car = entranceQueue.peek();
if (garages[0].contains(car.getPlateNumber())) {
entranceQueue.poll(); // 已在排队列中的车，直接取出
} else {
entranceQueue.offer(car); // 添加到排队队列的末尾等待下次取出
}
} else {
Car car = entranceQueue.poll();
garages[emptyGarageIndex].addCar(car);
emptySpotCount--;
}
}
}
// 模拟车辆出场
public void simulateCarExit() {
if (exitQueue.isEmpty()) {
return;
}
Car car = exitQueue.peek();
// 夜间停车不允许从22点较晚离开22点较早
if (car.getEnterTime() < NIGHT_END_TIME || car.getEnterTime() >= NIGHT_START_TIME) {
if (System.currentTimeMillis() < NIGHT_START_TIME && car.getExitTime() >= NIGHT_START_TIME) {
System.out.println("当前时间为夜间停车计费时间段内，不允许车牌号为" + car.getPlateNumber() + "的车辆现在离开停车场。");
return;
}
}
exitQueue.poll();
Car removedCar;
int garageIndex = -1;
for (int i = 0; i < garages.length; i++) {
if (garages[i].contains(car.getPlateNumber())) {
garageIndex = i;
break;
}
}
if (garageIndex != -1) {
removedCar = garages[garageIndex].removeCar(car.getPlateNumber());
long parkingTime = removedCar.getExitTime() - removedCar.getEnterTime();
double price = calcPrice(parkingTime);
emptySpotCount++;
System.out.println("离开了停车库，车牌号为" + removedCar.getPlateNumber() + "，停车时间为" + parkingTime +
"毫秒，需支付" + price + "元");
} else {
System.out.println("未找到车牌号为" + car.getPlateNumber() + "的车辆");
}
}
// 获取下一个应该出场的车辆
private Car getNextExitCar() {
Car nextCar = null;
long nextExitTime = Long.MAX_VALUE;
for (CarGarage garage : garages) {
for (Node node : ((CarGarageImpl) garage).garageMap.values()) {
for (; node != null; node = node.next) {
Car car = node.car;
if (car.getExitTime() < nextExitTime) {
nextExitTime = car.getExitTime();
nextCar = car;
}
}
}
}
return nextCar;
}
// 模拟出场排队
public void simulateExitQueue() {
if (getEmptySpotCount() == PARKING_LOT_CAPACITY) {
return;
}
while (exitQueue.size() < 1 && getNextExitCar() != null) {
Car nextCar = getNextExitCar();
exitQueue.offer(nextCar);
long waitTime = nextCar.getExitTime() - System.currentTimeMillis();
try {
Thread.sleep(waitTime);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
```
最后，可以使用以下方式模拟车辆进出停车场的情况：
```java
public static void main(String[] args) {
ParkingLot parkingLot = new ParkingLotImpl(5);
String[] plateNumbers = {"京A12345", "京A23456", "京A34567", "京A45678", "京A56789", "京A67890",
"京B12345", "京B23456", "京B34567", "京B45678", "京B56789", "京B67890"};
Random random = new Random();
// 模拟车辆进入停车场
Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
Car car = new Car(plateNumbers[random.nextInt(12)], System.currentTimeMillis());
parkingLot.enter(car);
}
}, 0, 500);
// 模拟车辆出场
timer.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
parkingLot.simulateExitQueue();
parkingLot.simulateCarExit();
}
}, 0, 1000);
// 模拟车辆进入小型车库
timer.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
parkingLot.simulateCarEnter();
}
}, 0, 5000);
}
```
以下是 Python 代码示例，实现了停车场管理系统的大致功能：
```python
import time
from collections import deque
# 停车场
class ParkingLot:
def __init__(self, num_entrances, num_exits, num_spaces):
self.num_entrances = num_entrances
self.num_exits = num_exits
self.num_spaces = num_spaces
self.entrance_queues = [deque() for _ in range(num_entrances)]
self.spaces = [Space() for _ in range(num_spaces)]
self.night_rate = 1 # 小型车夜间停车费用：1元/小时
# 停车
def park(self, car):
# 获取可用车位
space = self.get_empty_space()
if space is not None:
# 将车停入车位
space.park(car)
elif self.is_full():
# 如果停车场已满，则车辆排队等候
print(f"停车场已满，请{car}在入口处排队等候")
self.entrance_queues[car.entrance].append(car)
else:
raise Exception("Invalid parking state")
# 取车
def unpark(self, car):
space = self.find_space_by_car(car)
if space is not None:
duration = car.get_duration()
fee = 0 # 停车费用
if car.is_small:
# 夜间停车费用
hour = time.localtime(car.enter_time).tm_hour
if hour >= 22 or hour < 6:
fee = self.night_rate * duration / 3600
# 计算停车费用
fee += duration // 900 * 0.5
print(f"{car}停车时长为{duration//60}分钟，停车费用为{fee:.2f}元")
space.unpark(car)
# 检查排队等候的车辆
self.check_waiting_cars()
else:
raise Exception(f"{car}不在停车场内")
# 获取可用车位
def get_empty_space(self):
for space in self.spaces:
if not space.is_occupied():
return space
return None
# 根据车牌号查找车位
def find_space_by_car(self, car):
for space in self.spaces:
if space.car == car:
return space
return None
# 停车场是否已满
def is_full(self):
for space in self.spaces:
if not space.is_occupied():
return False
return True
# 检查排队等候的车辆
def check_waiting_cars(self):
for i in range(self.num_entrances):
if len(self.entrance_queues[i]) > 0:
car = self.entrance_queues[i][0]
space = self.get_empty_space()
if space is not None:
self.entrance_queues[i].popleft()
self.park(car)
print(f"{car}入场成功")
# 车位
class Space:
def __init__(self):
self.car = None
# 判断车位是否被占用
def is_occupied(self):
return self.car is not None
# 停车
def park(self, car):
self.car = car
car.enter_time = time.time()
# 取车
def unpark(self, car):
self.car = None
# 车辆
class Car:
def __init__(self, plate, entrance, is_small):
self.plate = plate # 车牌号码
self.entrance = entrance # 入口编号
self.is_small = is_small # 是否小型车
self.enter_time = None # 进场时间
# 获取停车时长，返回秒数
def get_duration(self):
if self.enter_time is not None:
return time.time() - self.enter_time
else:
return -1
def __str__(self):
return self.plate
if __name__ == '__main__':
lot = ParkingLot(2, 2, 25)
for i in range(80):
is_small = i % 5 == 0 # 每5个车位是一个小型车库
car = Car(f"京A{i:02d}", i % 2, is_small)
if i == 40:
lot.unpark(car) # 取走一辆不存在的车
else:
lot.park(car)
time.sleep(0.1) # 模拟每隔一段时间有车进入或离开停车场
```