程序代码：

//MyClass.h
#include<iostream>
const float PI=3.14f;
using namespace std;
///////////////////////////////////
//////下面定义了一个Circle类
class Circle
{
public:
    Circle();
    Circle(float);
    ~Circle();
    Get_R(float r);
    Get_Area();
    Get_Radius();//供派生类访问基类私有成员
    Display();
private:
    float Radius;
};
//////////////////////////////////////
////////下面定义了一个Boll类
class Ball:public Circle
{
public:
//    Ball();
//    Ball();
    ~Ball();
    Get_Volume();
    Get_Superficial_Area();
    Display();
};
////////////////////////////////////////
////////////下面定义了一个Cylinder类
class Cylinder:public Circle
{
    public:
        Cylinder();
        Cylinder(float);
        ~Cylinder();
        Get_Volume();
        Get_Height(float);
        Get_Superficial_Area();
        Display();
    private:
        float Height;
    
};
//////////////////////////////////////////////

//////////////////////////////////////////////
////////下面定义了一个Conicalness类
class Conicalness:public Circle
{
public:
    Conicalness();
    Conicalness(float);
    ~Conicalness();
    Get_Volume();
    Get_Superficial_Area();
    Display();
private:
    float Height;
};
//////////////////////////////////////////////////
//Myclass.cpp
#include"MyClass.h"
#include<cmath>
////////////////////////////
////////下面是Circle类成员函数的实现
Circle::Circle()
{
    Radius=0.0;
}//
Circle::Circle(float r)
{
    Radius=r;
}//
Circle::~Circle()
{
    cout<<"Circle destructor!"<<endl;
}//
Circle::Get_R(float r)
{
    Radius=r;
}//
Circle::Get_Radius()
{
    return Radius;
}//
Circle::Get_Area()
{
    return (PI*Radius*Radius);
}//
Circle::Display()
{
    cout<<"Radius:"<<Get_Radius()<<endl;
    cout<<"Area:"<<Get_Area()<<endl;
}//
//////////////////////////////////////////
////////////下面是Ball类成员函数的实现
Ball::~Ball()
{
    cout<<"Ball destructor!"<<endl;
}//
Ball::Get_Volume()
{
    return ((4.0*PI*Get_Radius()*Get_Radius()*Get_Radius())/3.0);
}//
Ball::Get_Superficial_Area()
{
    return (4.0*Get_Area());
}//
Ball::Display()
{
    Circle::Display();
    cout<<"Superficial_Area:"<<Get_Superficial_Area()<<endl;
    cout<<"Volume:"<<Get_Volume()<<endl;
}//
////////////////////////////////////////////
///////
///////////下面是Cylinder类成员函数的实现
Cylinder::Cylinder()
{
    Height=0;
}//
Cylinder::Cylinder(float height)
{
    Height=height;
}//
Cylinder::~Cylinder()
{
    cout<<"Cylinder destructor!"<<endl;
}//
Cylinder::Get_Volume()
{
    return float(PI*Get_Radius()*Get_Radius()*Height);
}//
Cylinder::Get_Superficial_Area()
{
    return((2.0)*PI*Get_Radius()*Height);
}//
Cylinder::Display()
{
    Circle::Display();
    cout<<"Superficial_Area:"<<Get_Superficial_Area()<<endl;
    cout<<"Volume:"<<Get_Volume()<<endl;
}//
///////////////////////////////////////////////
////////下面是Conicalness类成员函数的实现
Conicalness::Conicalness()
{
    Height=0;
}//
Conicalness::Conicalness(float height)
{
    Height=height;
}//
Conicalness::~Conicalness()
{
    cout<<"Conicalness destructor!"<<endl;
}//
Conicalness::Get_Volume()
{
    return ((1.0/3.0)*Height*Get_Area());
}//
Conicalness::Get_Superficial_Area()
{
    return(PI*Get_Radius()*sqrt(Height*Height+Get_Radius()*Get_Radius())+Get_Area());
}//
Conicalness::Display()
{
    Circle::Display();
    cout<<"Superficial_Area:"<<Get_Superficial_Area()<<endl;
    cout<<"Volume:"<<Get_Volume()<<endl;
}//
//////////////////////////////////////////////
//主函数
#include"MyClass.h"
int main()
{
    Circle *cir=new Circle;
    Ball *ball=new Ball;
    Cylinder *cyl=new Cylinder;
    Conicalness *con=new Conicalness;
    cout<<"------------Circle------------"<<endl;
    cir->Get_R(2.0);
    cir->Display();
    cout<<"------------Ball--------------"<<endl;
    ball->Get_R(3.0);
    ball->Display();
    cout<<"------------Cylinder----------"<<endl;
    cyl->Get_R(4.0);
    cyl->Display();
    cout<<"------------Conicalness-------"<<endl;
    con->Get_R(5.0);
    con->Display();
    cout<<"------------------------------"<<endl;
    delete cir;
    delete ball;
    delete con;
    delete cyl;
    return 0;
}

程序代码：

class Circle
{
public:
    Circle();
    Circle(float);
    ~Circle();
    Get_R(float r);
    float Get_Area();
    float Get_Radius();//供派生类访问基类私有成员
    Display();
private:
    float Radius;
};