LeetCode 1603. Design Parking System Solution

Problem

Design Parking System - LeetCode

Approach to Problem Solving

• This is a question about object creation in Java.

• The first solution demonstrates basic object creation, making it suitable for collaboration and future updates.

• The second solution is highly efficient for this specific problem, but it might be challenging to update later.

Github Link

https://github.com/eunhanlee/LeetCode_1603_DesignParkingSystem_Solution.git

1st Solution

class ParkingSystem {
    private int bigSlots;
    private int mediumSlots;
    private int smallSlots;

    /**
     * Creates a new ParkingSystem with specified slots for each vehicle type.
     *
     * @param big    Number of available slots for big vehicles.
     * @param medium Number of available slots for medium vehicles.
     * @param small  Number of available slots for small vehicles.
     */
    public ParkingSystem(int big, int medium, int small) {
        this.bigSlots = big;
        this.mediumSlots = medium;
        this.smallSlots = small;
    }

    /**
     * Adds a vehicle of the given type to the parking system.
     *
     * @param carType Type of the vehicle to be parked (1 for big, 2 for medium, 3 for small).
     * @return True if the vehicle is successfully parked, otherwise false.
     */
    public boolean addCar(int carType) {
        switch (carType) {
            case 1:
                if (this.bigSlots > 0) {
                    this.bigSlots--;
                    return true;
                }
                break;
            case 2:
                if (this.mediumSlots > 0) {
                    this.mediumSlots--;
                    return true;
                }
                break;
            case 3:
                if (this.smallSlots > 0) {
                    this.smallSlots--;
                    return true;
                }
                break;
        }
        return false;
    }
}

2nd Solution

class ParkingSystem {
    int[] slots;

    /**
     * Creates a new parking system with given slot sizes.
     *
     * @param big    Number of slots available for big vehicles.
     * @param medium Number of slots available for medium vehicles.
     * @param small  Number of slots available for small vehicles.
     */
    public ParkingSystem(int big, int medium, int small) {
        slots = new int[]{big, medium, small};
    }

    /**
     * Adds a vehicle of the given type to the parking system.
     *
     * @param carType Type of the vehicle to be parked (1 for big, 2 for medium, 3 for small).
     * @return True if the vehicle is successfully parked, otherwise false.
     */
    public boolean addCar(int carType) {
        return --slots[carType - 1] >= 0;
    }
}

Reference

Reasons for Using 'this' Keyword in Java Object Creation