用c++写一个汽车租赁系统

好的，下面是一个简单的汽车租赁系统的示例代码，仅供参考：

#include <iostream>
#include <string>
#include <vector>

using namespace std;

class Car {
public:
    string brand;
    string model;
    int year;
    double price;
    bool available;

    Car(string b, string m, int y, double p, bool a) {
        brand = b;
        model = m;
        year = y;
        price = p;
        available = a;
    }
};

class Rental {
public:
    string renter_name;
    Car car;
    int rental_days;

    Rental(string rn, Car c, int rd) {
        renter_name = rn;
        car = c;
        rental_days = rd;
    }

    double get_total_price() {
        return rental_days * car.price;
    }
};

int main() {
    vector<Car> cars;
    cars.push_back(Car("Toyota", "Camry", 2015, 50.0, true));
    cars.push_back(Car("Honda", "Accord", 2018, 70.0, true));
    cars.push_back(Car("Ford", "Mustang", 2020, 120.0, true));

    vector<Rental> rentals;

    while (true) {
        cout << "1. Rent a car" << endl;
        cout << "2. Return a car" << endl;
        cout << "3. Exit" << endl;
        cout << "Enter your choice: ";
        int choice;
        cin >> choice;

        if (choice == 1) {
            cout << "Available cars:" << endl;
            for (int i = 0; i < cars.size(); i++) {
                if (cars[i].available) {
                    cout << i << ". " << cars[i].brand << " " << cars[i].model << " (" << cars[i].year << ") - $" << cars[i].price << "/day" << endl;
                }
            }

            int car_choice;
            cout << "Enter car choice: ";
            cin >> car_choice;

            if (cars[car_choice].available) {
                string renter_name;
                cout << "Enter renter name: ";
                cin >> renter_name;

                int rental_days;
                cout << "Enter rental days: ";
                cin >> rental_days;

                cars[car_choice].available = false;
                rentals.push_back(Rental(renter_name, cars[car_choice], rental_days));
                cout << "Successfully rented " << cars[car_choice].brand << " " << cars[car_choice].model << " to " << renter_name << "." << endl;
            } else {
                cout << "Car is not available." << endl;
            }
        } else if (choice == 2) {
            cout << "Rented cars:" << endl;
            for (int i = 0; i < rentals.size(); i++) {
                cout << i << ". " << rentals[i].car.brand << " " << rentals[i].car.model << " (" << rentals[i].car.year << ") - $" << rentals[i].car.price << "/day - Rented to " << rentals[i].renter_name << " for " << rentals[i].rental_days << " days." << endl;
            }

            int rental_choice;
            cout << "Enter rental choice: ";
            cin >> rental_choice;

            if (rental_choice < rentals.size()) {
                double total_price = rentals[rental_choice].get_total_price();
                cout << "Total price for " << rentals[rental_choice].rental_days << " days is $" << total_price << "." << endl;

                cars.push_back(rentals[rental_choice].car);
                cars.back().available = true;
                rentals.erase(rentals.begin() + rental_choice);
                cout << "Successfully returned " << cars.back().brand << " " << cars.back().model << "." << endl;
            } else {
                cout << "Invalid rental choice." << endl;
            }
        } else if (choice == 3) {
            break;
        } else {
            cout << "Invalid choice." << endl;
        }
    }

    return 0;
}

这个系统使用了两个类：`Car` 和 `Rental`，分别表示汽车和租赁情况。主函数中创建了一个汽车列表和一个租赁列表，然后进入一个循环，让用户进行操作。

用户可以选择租用汽车或归还汽车，当租用汽车时，系统会列出当前可用的汽车列表，并要求用户输入租用的汽车、租用天数和租用人的姓名。当归还汽车时，系统会列出当前已租用的汽车列表，并要求用户输入要归还的租赁记录。系统会计算出租赁总价，并将汽车标记为可用状态，从租赁列表中删除相应的记录。

这只是一个简单的示例代码，实际的汽车租赁系统可能需要更复杂的功能和更完善的界面设计。