README_EN.md

1603. Design Parking System

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Description

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

Solutions

Python3

class ParkingSystem:

    def __init__(self, big: int, medium: int, small: int):
        self.cnt = [0, big, medium, small]

    def addCar(self, carType: int) -> bool:
        if self.cnt[carType] == 0:
            return False
        self.cnt[carType] -= 1
        return True


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

Java

class ParkingSystem {
    private int[] cnt;

    public ParkingSystem(int big, int medium, int small) {
        cnt = new int[]{0, big, medium, small};
    }

    public boolean addCar(int carType) {
        if (cnt[carType] == 0) {
            return false;
        }
        --cnt[carType];
        return true;
    }
}

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

C++

class ParkingSystem {
public:
    vector<int> cnt;

    ParkingSystem(int big, int medium, int small) {
        cnt = {0, big, medium, small};
    }

    bool addCar(int carType) {
        if (cnt[carType] == 0) return false;
        --cnt[carType];
        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);
 */

Go

type ParkingSystem struct {
	cnt []int
}

func Constructor(big int, medium int, small int) ParkingSystem {
	return ParkingSystem{[]int{0, big, medium, small}}
}

func (this *ParkingSystem) AddCar(carType int) bool {
	if this.cnt[carType] == 0 {
		return false
	}
	this.cnt[carType]--
	return true
}

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

Rust

struct ParkingSystem {
    list: [i32; 3],
}


/**
 * `&self` means the method takes an immutable reference.
 * If you need a mutable reference, change it to `&mut self` instead.
 */
impl ParkingSystem {

    fn new(big: i32, medium: i32, small: i32) -> Self {
        Self {
            list: [big, medium, small]
        }
    }

    fn add_car(&mut self, car_type: i32) -> bool {
        let i = (car_type - 1) as usize;
        if self.list[i] == 0 {
            return false;
        }
        self.list[i] -= 1;
        true
    }
}

/**
 * Your ParkingSystem object will be instantiated and called as such:
 * let obj = ParkingSystem::new(big, medium, small);
 * let ret_1: bool = obj.add_car(carType);
 */

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