mirrors
/
system-design-primer
mirror of https://github.com/donnemartin/system-design-primer.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Added python code example for parking lot - object oriented system design

pull/507/head
pthapa 2021-02-06 14:47:23 -05:00
parent 478a7d76fb
commit 61d889e6f4
2 changed files with 469 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

275
solutions/object_oriented_design/parking_lot/input_parking_lot_example.json Normal file
View File

@ -0,0 +1,275 @@
{
"total_number_of_parking_lot": 1,
"total_number_of_levels": 2,
"number_of_rows_in_each_level": 2,
"number_of_spots_in_each_row": 10,
"levels": {
"level_1": [
{
"level": 1,
"row": 1,
"spot_number": 1,
"spot_size": 0
},
{
"level": 1,
"row": 1,
"spot_number": 2,
"spot_size": 0
},
{
"level": 1,
"row": 1,
"spot_number": 3,
"spot_size": 1
},
{
"level": 1,
"row": 1,
"spot_number": 4,
"spot_size": 1
},
{
"level": 1,
"row": 1,
"spot_number": 5,
"spot_size": 1
},
{
"level": 1,
"row": 1,
"spot_number": 6,
"spot_size": 2
},
{
"level": 1,
"row": 1,
"spot_number": 7,
"spot_size": 2
},
{
"level": 1,
"row": 1,
"spot_number": 8,
"spot_size": 2
},
{
"level": 1,
"row": 1,
"spot_number": 9,
"spot_size": 2
},
{
"level": 1,
"row": 1,
"spot_number": 10,
"spot_size": 2
},
{
"level": 1,
"row": 2,
"spot_number": 1,
"spot_size": 0
},
{
"level": 1,
"row": 2,
"spot_number": 2,
"spot_size": 0
},
{
"level": 1,
"row": 2,
"spot_number": 3,
"spot_size": 1
},
{
"level": 1,
"row": 2,
"spot_number": 4,
"spot_size": 1
},
{
"level": 1,
"row": 2,
"spot_number": 5,
"spot_size": 1
},
{
"level": 1,
"row": 2,
"spot_number": 6,
"spot_size": 2
},
{
"level": 1,
"row": 2,
"spot_number": 7,
"spot_size": 2
},
{
"level": 1,
"row": 2,
"spot_number": 8,
"spot_size": 2
},
{
"level": 1,
"row": 2,
"spot_number": 9,
"spot_size": 2
},
{
"level": 1,
"row": 2,
"spot_number": 10,
"spot_size": 2
}
],
"level_2": [
{
"level": 2,
"row": 1,
"spot_number": 1,
"spot_size": 0
},
{
"level": 2,
"row": 1,
"spot_number": 2,
"spot_size": 0
},
{
"level": 2,
"row": 1,
"spot_number": 3,
"spot_size": 1
},
{
"level": 2,
"row": 1,
"spot_number": 4,
"spot_size": 1
},
{
"level": 2,
"row": 1,
"spot_number": 5,
"spot_size": 1
},
{
"level": 2,
"row": 1,
"spot_number": 6,
"spot_size": 2
},
{
"level": 2,
"row": 1,
"spot_number": 7,
"spot_size": 2
},
{
"level": 2,
"row": 1,
"spot_number": 8,
"spot_size": 2
},
{
"level": 2,
"row": 1,
"spot_number": 9,
"spot_size": 2
},
{
"level": 2,
"row": 1,
"spot_number": 10,
"spot_size": 2
},
{
"level": 2,
"row": 2,
"spot_number": 1,
"spot_size": 0
},
{
"level": 2,
"row": 2,
"spot_number": 2,
"spot_size": 0
},
{
"level": 2,
"row": 2,
"spot_number": 3,
"spot_size": 1
},
{
"level": 2,
"row": 2,
"spot_number": 4,
"spot_size": 1
},
{
"level": 2,
"row": 2,
"spot_number": 5,
"spot_size": 1
},
{
"level": 2,
"row": 2,
"spot_number": 6,
"spot_size": 2
},
{
"level": 2,
"row": 2,
"spot_number": 7,
"spot_size": 2
},
{
"level": 2,
"row": 2,
"spot_number": 8,
"spot_size": 2
},
{
"level": 2,
"row": 2,
"spot_number": 9,
"spot_size": 2
},
{
"level": 2,
"row": 2,
"spot_number": 10,
"spot_size": 2
}
]
},
"users":{
"1":{
"license_plate":"123-456",
"vehicle_type":"CAR",
"vehicle_size":"MEDIUM"
},
"2":{
"license_plate": "123-457",
"vehicle_type": "CAR",
"vehicle_size": "LARGE"
},
"3":{
"license_plate": "123-111",
"vehicle_type": "MOTORCYCLE",
"vehicle_size": "SMALL"
},
"4":{
"license_plate": "123-999",
"vehicle_type": "CAR",
"vehicle_size": "LARGE"
}
}
}

194
solutions/object_oriented_design/parking_lot/parking_lot_example.py Normal file
View File

@ -0,0 +1,194 @@
import json
from enum import Enum
# design a parking lot
# assumption is vehicle size corresponds to spot size
"""
vehicle_size_small; spot_size = 0 => can park Motorcycle
vehicle_size_medium ; spot_size = 1 => can park Motorcycle or Car
vehicle_size_large ; spot_size = 2 => can park Motorcycle or Car
Bus can park if we have 5 consecutive "large" spots
"""
class VehicleType(Enum):
MOTORCYCLE = 'MOTORCYCLE',
CAR = 'CAR',
BUS = 'BUS'
class VehicleSize(Enum):
SMALL = 0
MEDIUM = 1
LARGE = 2
VERY_LARGE = 10
class Vehicle(object):
def __init__(self, vehicle_size, license_plate, vehicle_type):
self.vehicle_size = vehicle_size
self.license_plate = license_plate
self.vehicle_type = vehicle_type
self.spots_taken = []
def __repr__(self):
return """
vehicle_size : {vehicle_size},
license_plate : {license_plate},
vehicle_type : {vehicle_type},
spots_taken : {spots_taken}
""".format(vehicle_size=self.vehicle_size, license_plate=self.license_plate,
vehicle_type=self.vehicle_type, spots_taken=self.spots_taken)
def clear_spots(self):
for spot in self.spots_taken:
spot.remove_vehicle(self)
self.sport_taken = []
def take_spot(self, spot):
self.spots_taken.append(spot)
class ParkingLot(object):
def __init__(self, num_levels):
self.num_levels = num_levels
self.levels = []
def __repr__(self):
return """
number_of_levels : {num_levels},
levels : {levels}
""".format(num_levels=self.num_levels, levels=self.levels)
def park_vehicle(self, vehicle):
for level in self.levels:
spot = level.reserve_spot(vehicle)
if spot:
print(" == TICKET PRINTING - PARKING SPOT RESERVED == ")
print(vehicle)
return True
else:
return False
class ParkingLevel(object):
def __init__(self, level, total_spots):
self.level = level
self.num_spots = total_spots
self.available_spots = total_spots
self.parking_spots = []
self.reserved_spots = []
def __repr__(self):
return """
level : {level},
number_of_spots : {num_spots},
avialable_spots : {available_spots},
parking_spots : {parking_spots},
reserved_spots : {reserved_spots}
""".format(level=self.level, num_spots=self.num_spots, available_spots=self.available_spots,
parking_spots=self.parking_spots, reserved_spots=self.reserved_spots)
def spot_reserved(self, index, spot):
self.reserved_spots.append(spot)
self.parking_spots.pop(index)
self.available_spots -= 1
def reserve_spot(self, vehicle):
# for motorcycle or car for exact match
for index, parking_spot in enumerate(self.parking_spots):
if parking_spot.spot_size == vehicle.vehicle_size.value:
# parking_spot.vehicle = vehicle
self.spot_reserved(index, parking_spot)
vehicle.spots_taken.append(parking_spot)
return parking_spot
# for motorcycle or car no exact match;ie vehicle less then size of spot
for index, parking_spot in enumerate(self.parking_spots):
if parking_spot.spot_size > vehicle.vehicle_size.value:
# parking_spot.vehicle = vehicle
self.spot_reserved(index, parking_spot)
vehicle.spots_taken.append(parking_spot)
return parking_spot
# for bus , find 5 consecutive free spot
for index, parking_spot in enumerate(self.parking_spots):
if parking_spot.spot_size < vehicle.vehicle_size.value:
# if ... sliding window for checking 5 consecutive free spot
# loop parking_spot.vehicle = vehicle
# loop self.spot_reserved(index, parking_spot)
# loop vehicle.spots_taken.append(parking_spot)
# return parking_spot as string using ''.join()
pass
return False
class ParkingSpot(object):
def __init__(self, level, row, spot_number, spot_size):
self.level = level
self.row = row
self.spot_number = spot_number
self.spot_size = spot_size
self.vehicle = None
# logic for bus pending
def __repr__(self):
return """
level : {level},
row : {row},
spot_number : {spot_number},
spot_size : {spot_size}
vehicle : {vehicle}
""".format(level=self.level, row=self.row, spot_number=self.spot_number,
vehicle=self.vehicle, spot_size=self.spot_size)
if __name__ == '__main__':
try:
f = open('input_parking_lot_example.json')
data = json.load(f)
except Exception as E:
print("Error opening input_parking_lot_example.json file")
print(E)
number_of_rows = data['number_of_rows_in_each_level']
number_of_spots_in_each_row = data['number_of_spots_in_each_row']
total_number_of_spots_in_level = number_of_rows * number_of_spots_in_each_row
number_of_levels = data['total_number_of_levels']
parking_lot = ParkingLot(num_levels=number_of_levels)
for level_name, level in data['levels'].items():
parking_level = ParkingLevel(level=level_name, total_spots=total_number_of_spots_in_level)
for spot in level:
parking_spot = ParkingSpot(
level=spot['level'],
row=spot['row'],
spot_number=spot['spot_number'],
spot_size=spot['spot_size']
)
parking_level.parking_spots.append(parking_spot)
parking_lot.levels.append(parking_level)
input_vehicle_list = []
for user_name, user in data['users'].items():
vehicle_q_id = user_name
vehicle = Vehicle(
vehicle_size=VehicleSize["MEDIUM"],
license_plate=user['license_plate'],
vehicle_type=VehicleType["CAR"])
input_vehicle_list.append(vehicle)
# processing of inputs in input_list
for idx, input_vehicle in enumerate(input_vehicle_list):
parking_lot.park_vehicle(input_vehicle)