public enum VehicleType {
  CAR, TRUCK, ELECTRIC, VAN, MOTORBIKE
}

public enum ParkingSpotType {
  HANDICAPPED, COMPACT, LARGE, MOTORBIKE, ELECTRIC
}

public abstract class Vehicle {
  private String licenseNumber;
  private final VehicleType type;
  private ParkingTicket ticket;

  public Vehicle(VehicleType type) {
    this.type = type;
  }

  public void assignTicket(ParkingTicket ticket) {
    this.ticket = ticket;
  }
}

public class Car extends Vehicle {
  public Car() {
    super(VehicleType.CAR);
  }
}

public class Van extends Vehicle {
  public Van() {
    super(VehicleType.VAN);
  }
}

public class Truck extends Vehicle {
  public Truck() {
    super(VehicleType.TRUCK);
  }
}

// Similarly we can define classes for Motorcycle and Electric vehicles etc.

public abstract class ParkingSpot {
  private String number;
  private boolean free;
  private final ParkingSpotType type;
  private Vehicle vehicle;

  public boolean isFree() {
      return free;
  }

  public ParkingSpot(ParkingSpotType type) {
    this.type = type;
  }

  public boolean assignSpot(Vehicle vehicle) {
    this.vehicle = vehicle;
    free = false;
  }

  public boolean freeSpot() {
    this.vehicle = null;
    free = true;
  }
}

public class HandicappedSpot extends ParkingSpot {
  public HandicappedSpot() {
    super(ParkingSpotType.HANDICAPPED);
  }
}

public class CompactSpot extends ParkingSpot {
  public CompactSpot() {
    super(ParkingSpotType.COMPACT);
  }
}

public class LargeSpot extends ParkingSpot {
  public LargeSpot() {
    super(ParkingSpotType.LARGE);
  }
}

public class MotorbikeSpot extends ParkingSpot {
  public MotorbikeSpot() {
    super(ParkingSpotType.MOTORBIKE);
  }
}

public class ElectricSpot extends ParkingSpot {
  public ElectricSpot() {
    super(ParkingSpotType.ELECTRIC);
  }
}

public class ParkingFloor {
  private String name;
  private HashMap<String, HandicappedSpot> handicappedSpots;
  private HashMap<String, CompactSpot> compactSpots;
  private HashMap<String, LargeSpot> largeSpots;
  private HashMap<String, MotorbikeSpot> motorbikeSpots;
  private HashMap<String, ElectricSpot> electricSpots;

  public ParkingFloor(String name) {
    this.name = name;
  }
}  

public class ParkingLot {
    private String name;
    private HashMap<String, ParkingFloor> parkingFloors;
  
    // private constructor to restrict for singleton
    private ParkingLot() {
    
    }

    // singleton ParkingLot to ensure only one object of ParkingLot in the system
    private static class ParkingLotHolder {
        private static final ParkingLot INSTANCE = new ParkingLot();
    }
  
    // static method to get the singleton instance of ParkingLot
    public static ParkingLot getInstance() {
        return ParkingLotHolder.INSTANCE;
    }
  }