设计一个交通工具类族

设计交通工具类族: 开发一个名为Vehicle 的类的层次体系。创建两个类Taxi 和Truck，均以公有模式从类Vehicle 中继承而来。Taxi 类中应包含一个数据成员passenger说明其是否载客。Truck类应包含一个数据成员cargo说明其是否载货。根据题后附的测试程序输出结果 为类Vehicle添加必要的数据成员,并为所有类添加必要的函数来控制和访问类的数据。编写一段测试程序，将Vehicle对象、Truck 对象和Taxi对象打印到屏幕。（30分）
测试程序输出实例为：
Vehicle
              Number of doors: 2
              Number of cylinders: 6
              Transmission type: 3
              Color: blue
              Fuel level: 14.6
Taxi
              Number of doors: 4
              Number of cylinders: 6
              Transmission type: 5
              Color: yellow
              Fuel level: 3.3
              The taxi has no passengers.
Truck
              Number of doors: 2
              Number of cylinders: 16
              Transmission type: 8
              Color: black
              Fuel level: 7.54
              The truck is carrying cargo.

就是测试多态性呗，有门啥的一些属性

class Vehicle
{
    private:
        int doors;
        int cylinders;
        int transmission;
        string color;
        float fuel;
    public:
        Vehicle() {}
        Vehicle(int d,int c,int t,string col,float f)
        {
            doors = d;
            cylinders = c;
            transmission = t;
            color = col;   
            fuel = f;
        }
        virtual void print()
        {
            cout<<Number of doors:"<<doors<<endl;
            cout<<Number of cylinders:"<<cylinders<<endl;
            cout<<Transmisson type:"<<transmission<<endl;
            cout<<Color:"<<color<<endl;
            cout<<"Fuel level:"<<fuel<<endl;
        }
};

class Taxi : public Vehicle
{
    private:
        int passagers;
    public:
        Taxi() {}
        Taxi(int d,int c,int t,string col,float f,int p) : Vehicle(d,c,t,col,f)
        {
            passagers = p;
        }
        virtual void print()
        {
            Vehicle::Print();
            if(passagers == 0)
                cout<<"the taxi has no passengers"<<endl;
            else
                cout<<"Ther taxi is carrying passengers."<<endl;
        }
};

class Trunk: public Vehicle
{
    private:
        int cargo;
    public:
        Trunk() {}
        Trunk(int d,int c,int t,string col,float f,int car) : Vehicle(d,c,t,col,f)
        {
            cargp = cargo;
        }
        virtual void print()
        {
            Vehicle::Print();
            if(cargo == 0)
                cout<<"the trunk has no cargo"<<endl;
            else
                cout<<"Ther trunk is carrying cargo."<<endl;
        }
};

int main()
{
    Vehicle *p = new Vehicle(2,6,3,"blue",14.6);
    p->print();
    delete p;
    p = new Taxi(4,6,5,"yellow",3.3,0);
    p->print();
    delete p;
    p = new Trunk(2,16,8,"black",7.5,10);
    p->print();
    delete p;
}