Design Parking System

Amarjit Dhillon
2 min readFeb 10, 2022

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Problem Statement ❓

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 the object of the ParkingSystem class. The number of slots for each parking space is 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

How to handle diff types of 🅿️?

  • In the constructor, we can create a hashmap to hold the various types of parking
  • This hashmap will be of type int:int , where the key is the parking type and value is the space available
  • Values of keys represent 1 for big, 2 for medium and 3 for small
  • For example 2:15 means that 15 cars of medium size parking is available
  • Other things in this question are just based on simple OOPS concepts

Let’s code it up 🚗

For more such solutions clone https://github.com/amarjitdhillon/CP_2021 repo. For questions, please comment on the Gist

Peace ❤

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