#include <iostream>

using namespace std;

const int length = 3;

class Car
{
    private:
        int num;
        double gas;

    public:
        Car();
        void setCar(int,double);
        void show();
};

Car::Car()
{
    num = 0;
    gas = 0.0;
    cout<<"生產了汽車。\n";
}

void Car::setCar(int n, double g)
{
    num = n;
    gas = g;
    cout<<"已使車號為"<<num<<"，使汽油量為"<<gas<<"。\n";
}

void Car::show()
{
    cout<<"車號是"<<num<<"。\n";
    cout<<"汽油量是"<<gas<<"。\n";
}

int main()
{
    // method 4
    Car** cars = new Car*[length];
    for (int i=0; i<length; i++)
    {
        cars[i] = new Car();
    }

    cars[0]->setCar(1234, 20.5);
    cars[1]->setCar(2345, 30.5);
    cars[2]->setCar(3456, 40.5);

    for(int i=0; i<length; i++)
    {
        cars[i]->show();
    }

    return 0;
}