Brooke

一、題目

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

 

二、程式作法

 public class ParkingSystem
{
    private int[] lots = new int[3];
    public ParkingSystem(int big, int medium, int small)
    {
        lots[0] = big;
        lots[1] = medium;
        lots[2] = small;
    }

    public bool AddCar(int carType)
    {
        if (lots[carType - 1] < 1) return false;
        lots[carType - 1]--;
        return true;
    }
}

/**
 * Your ParkingSystem object will be instantiated and called as such:
 * ParkingSystem obj = new ParkingSystem(big, medium, small);
 * bool param_1 = obj.AddCar(carType);
 */

 

三、思路筆記

略