约束和假设
- 我们应该支持哪种类型的车辆？
- 每种车型占用的停车位数量是否不同？
- Yes
- Motorcycle spot -> Motorcycle
- Compact spot -> Motorcycle, Car
- Large spot -> Motorcycle, Car
- Bus can park if we have 5 consecutive “large” spots
- 停车场是否有多层？
编码实现
from abc import AMCMeta, abstractmethodclass VehicleSize(Enum):MOTORCYCLE = 0COMPACT = 1LARGE = 2class Vehicle(metaclass=ABCMeta):def __init__(self, vehicle_size, license_plate, spot_size):self.vehicle_size = vehicle_size self.license_plate = license_plateself.spot_size = spot_sizeself.spots_taken = []def clear_spots(self):for spot in self.spots_taken:spot.remove_vehicle(self)self.spots_taken = []def take_spot(self, spot):self.spots_taken.append(spot)@abstractmethoddef can_fit_in_spot(self,spot):passclass Motorcycle(Vehicle):def __init__(self, license_plate): super(Motorcycle, self).__init__(VehicleSize.MOTORCYCLE, license_plate, spot_size=1)def can_fix_in_spot(self, spot):return trueclass Car(Vehicle):def __init__(self, license_plate):super(Car, self).__init__(VehicleSize.COMPACT, license_plate, spot_size)def can_fit_in_spot(self, spot):return True if (spot.size == LARGE or spot.size == COMPACT) else Falseclass Bus(Vehicle):def __init__(self, license_plate):super(Bus, self).__init__(VehicleSize.LARGE, license_plate, spot_size=5)def can_fit_in_spot(self, spot):return True if spot.size == LARGE else Falseclass ParkingLot(object):def __init__(self, num_levels):self.num_levels = num_levelsself.levels = []def park_vehicle(self, vehicle):for level in levels:if level.park_vehicle(vehicle):return Truereturn Falseclass Level(object):SPOTS_PER_ROW = 10def __init__(self, floor, total_spots):self.floor = floorself.num_spots = total_spotsself.available_spots = 0self.parking_spots = []def spot_freed(self):self.available_spots += 1def park_vehicle(self, vehicle):spot = self._find_available_spot(vehicle)if spot is None:return Noneelse:spot.park_vehicle(vehicle)return spotdef _find_available_spot(self, vehicle):'''Find an available spot where vehicle can fix, or return None'''def _park_starting_at_spot(self, spot, vehicle):'''Occupy starting at spot.spot_number to vehicle.spot_size'''class ParkingSpot(object):def __init__(self, level, row, spot_numberm, spot_size, vehicle_size):self.level = levelself.row = rowself.spot_numer = spot_numberself.spot_size = spot_sizeself.vehicle_size = vehicle_sizeself.vehicle = Nonedef is_available(self):return True if self.vehicle is None else Falsedef can_fit_vehicle(self, vehicle):if self.vehicle is not None:return Falsereturn vehicle.can_fit_in_spot(self)def park_vehicle(self, vehicle): def remove_vehicle(self):
