1603. Design Parking System

题目

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

题目大意

请你给一个停车场设计一个停车系统。停车场总共有三种不同大小的车位：大，中和小，每种尺寸分别有固定数目的车位。

请你实现 ParkingSystem 类：

• ParkingSystem(int big, int medium, int small) 初始化 ParkingSystem 类，三个参数分别对应每种停车位的数目。
• bool addCar(int carType) 检查是否有 carType 对应的停车位。 carType 有三种类型：大，中，小，分别用数字 1， 2 和 3 表示。一辆车只能停在  carType 对应尺寸的停车位中。如果没有空车位，请返回 false ，否则将该车停入车位并返回 true 。

解题思路

• 简单题。分别用 3 个变量表示大，中和小车位。addCar() 判断这 3 个变量是否还有空车位即可。

代码

package leetcode

type ParkingSystem struct {
	Big    int
	Medium int
	Small  int
}

func Constructor(big int, medium int, small int) ParkingSystem {
	return ParkingSystem{
		Big:    big,
		Medium: medium,
		Small:  small,
	}
}

func (this *ParkingSystem) AddCar(carType int) bool {
	switch carType {
	case 1:
		{
			if this.Big > 0 {
				this.Big--
				return true
			}
			return false
		}
	case 2:
		{
			if this.Medium > 0 {
				this.Medium--
				return true
			}
			return false
		}
	case 3:
		{
			if this.Small > 0 {
				this.Small--
				return true
			}
			return false
		}
	}
	return false
}

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

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