《第十三周实验报告任务4》

/* (程序头部注释开始)
* 程序的版权和版本声明部分
* Copyright (c) 2011, 烟台大学计算机学院学生
* All rights reserved.
* 文件名称：   《抽象基类的应用》                        
* 作    者：       刘江波                      
* 完成日期：    2012     年   5    月    15    日
* 版 本 号：     v.05153    

* 对任务及求解方法的描述部分
* 问题描述：

  设计一个抽象类CSolid，含有两个求表面积及体积的纯虚函数。设计个派生类CCube、CBall、CCylinder，分别表示正方体、球体及圆柱体。在main()函数中，定义基类的指针p(CSolid *p;)，利用p指针，输出正方体、球体及圆柱体对象的表面积及体积。

* 程序头部的注释结束
*/

#include<iostream>   
using namespace std;  
  
const double PI = 3.14159;  
  
class CSolid  
{  
public:  
    virtual double area() const =0;  
    virtual double volume() const =0;  
};  
  
class CCube: public CSolid  
{  
public:  
    CCube(double length);  
    virtual double area() const;  
    virtual double volume() const;  
    void show_area();  
    void show_volume();  
protected:  
    double length;  
};  
  
class CBall: public CSolid  
{  
public:  
    CBall(double radius);  
    virtual double area() const;  
    virtual double volume() const;  
protected:  
    double radius;  
};  
  
class CCylinder: public CSolid  
{  
public:  
    CCylinder(double height, double radius);  
    virtual double area() const;  
    virtual double volume() const;  
    void show_area();  
    void show_volume();  
protected:  
    double height;  
    double radius;  
};  
  
CCube::CCube(double length)  
{  
    this->length = length;  
}  
  
double CCube::area() const  
{  
    return (this->length * this->length * 6);  
}  
  
double CCube::volume() const  
{  
    return (this->length * this->length * this->length);  
}  
  
  
CBall::CBall(double radius)  
{  
    this->radius = radius;  
}  
  
double CBall::area() const  
{  
    return (4 * PI * this->radius * this->radius);  
}  
  
double CBall::volume() const  
{  
    return (PI * this->radius * this->radius * this->radius * 3 / 4);  
}  
  
CCylinder::CCylinder(double height, double radius)  
{  
    this->height = height;  
    this->radius = radius;  
}  
  
double CCylinder::area() const  
{  
    return (2 * (PI * this->radius * this->radius) + this->height * (2 * PI * this->radius));  
}  
  
double CCylinder::volume() const  
{  
    return (PI * this->radius * this->radius * this->height);  
}  
  
int main()  
{  
    CSolid *p;  
  
    CCube ccube(5);  
    CBall cball(4);  
    CCylinder ccylinder(10, 2);  
  
    p = &ccube;  
  
    cout << "正方体的表面积是:" << p->area() << endl;  
    cout << "正方体的体积是:" << p->volume() << endl;  
  
    p = &cball;  
  
    cout << "球体的表面积是:" << p->area() << endl;  
    cout << "球体的体积是:" << p->volume() << endl;  
  
    p = &ccylinder;  
  
    cout << "圆柱体的表面积是:" << p->area() << endl;  
    cout << "圆柱体的体积是:" << p->volume() << endl;  
  
    system("pause");  
    return 0;  
}  

 

抽象基类太实用了