1603-design-parking-system.rb

# frozen_string_literal: true

# 1603. Design Parking System
# https://leetcode.com/problems/design-parking-system
# Easy

=begin
Design a parking system for a parking lot. The parking lot has three kinds of parking spaces: big, medium, and small, with a fixed number of slots for each size.
Implement the ParkingSystem class:
* ParkingSystem(int big, int medium, int small) Initializes object of the ParkingSystem class. The number of slots for each parking space are given as part of the constructor.
* bool addCar(int carType) Checks whether there is a parking space of carType for the car that wants to get into the parking lot. carType can be of three kinds: big, medium, or small, which are represented by 1, 2, and 3 respectively. A car can only park in a parking space of its carType. If there is no space available, return false, else park the car in that size space and return true.

Example 1:
Input
["ParkingSystem", "addCar", "addCar", "addCar", "addCar"]
[[1, 1, 0], [1], [2], [3], [1]]
Output
[null, true, true, false, false]
Explanation
ParkingSystem parkingSystem = new ParkingSystem(1, 1, 0);
parkingSystem.addCar(1); // return true because there is 1 available slot for a big car
parkingSystem.addCar(2); // return true because there is 1 available slot for a medium car
parkingSystem.addCar(3); // return false because there is no available slot for a small car
parkingSystem.addCar(1); // return false because there is no available slot for a big car. It is already occupied.

Constraints:
* 0 <= big, medium, small <= 1000
* carType is 1, 2, or 3
* At most 1000 calls will be made to addCar
=end

class ParkingSystem
=begin
    :type big: Integer
    :type medium: Integer
    :type small: Integer
=end
  def initialize(big, medium, small)
    @space = [big, medium, small]
  end

=begin
    :type car_type: Integer
    :rtype: Boolean
=end
  def add_car(car_type)
    -1 < @space[car_type - 1] -= 1
  end
end

# Your ParkingSystem object will be instantiated and called as such:
# obj = ParkingSystem.new(big, medium, small)
# param_1 = obj.add_car(car_type)