Parking System design

It's necessary to implement simple in-memory parking lot system.

The implementation is divided into several branches:

1. branch #1

First requirements

• there's one spot type
• there's one vehicle type: car
• park/unpark methods
• parking lot capacity is restricted, if unable to park a vehicle, return false

Additional requirements

• a new vehicle type is added - motorcycle
• a spot can fit either 1 car or 2 motorcycles
• charging for parking

2. branch #2

Requirements

• there are several vehicle types: motorcycle, car, truck
• there are several spot types: small, compact, large.
• spot types work as follows:
  small spots can fit only motorcycles
  compact spots fit motorcycles or cars
  large spots fit any vehicle type
• park lot should provide parking and unparking features
• parking lot capacity is restricted, if unable to park a vehicle, return false

Optional requirements

• add charging for parking(we can assume that a charge is calculated according to a spot type)
• we're always running out of spots, we can modify out parking spot rules as follows:
  compact spots can fit 2 motorcycles or only 1 car, large spots can fit 3 motorcycles or 1 car and 1 motorcycle or just 1 truck

Paying attention to the following points

• avoiding the if else blocks, instanceof keyword
• the time complexity for finding a spot