圆柱类

#include <iostream>

using namespace std;

class Point

{

public:

    Point(double xx,double yy)

    {

        x=xx;

        y=yy;

    }

    void Show_point()

    {

        cout<<"中心坐标为:"<<"("<<x<<","<<y<<")"<<endl;

    }

private:

    double x;

    double y;

};

class Circle:public Point

{

public:

    Circle(double xx,double yy,double rr):Point(xx,yy),r(rr){}

    double area()

    {

        return 3.14*r*r;

    }

    double circum()/*周长*/

    {

        return 2*3.14*r;

    }

private:

    double r;

};

class Cylinder:public Circle

{

public:

    Cylinder(double xx,double yy,double rr,double hh):Circle(xx,yy,rr),h(hh){}

    void area()

    {

        cout<<"圆柱的表面积为:"<<h*Circle::circum()+2*Circle::area()<<endl;

    }

    void volume()

    {

        cout<<"圆柱的体积为:"<<h*Circle::area()<<endl;

    }

private:

    double h;

};

int main()

{

    Cylinder a(2,2,3,4);

    a.Show_point();

    a.area();

    a.volume();

    return 0;

}