各种物体的表面积体积

/*
*烟台大学计算机学院
*文件名称：main.cpp
*作    者：王者健
*完成日期：2016年6月15日
*版 本 号：codeblocks 16.01
*问题描述：
*输入描述：
*程序输出：
*/
#include <iostream>
#include<Cmath>
using namespace std;
const double pai=3.1415926;
class CSolid
{
public:
virtual double SurfaceArea()const=0;
virtual double Volume()const =0;
};
//立方体类
class CCube:public CSolid
{
public:
CCube(double len=0);
double SurfaceArea()const;
double Volume()const;
private:
double length;

};

CCube::CCube(double len)
{
length=len;
}
double CCube::SurfaceArea()const
{
double c;
c=6*length*length;
return c;
}
double CCube::Volume()const
{
double c;
c=length*length*length;
return c;
}
//球类
class CBall: public CSolid
{
private:
double radius;
public:
CBall(double r=0);
double SurfaceArea()const;
double Volume()const;
};
CBall::CBall(double r)
{
radius=r;
}
double CBall::SurfaceArea()const
{
double c;
c=4*pai*radius*radius;
return c;
}
double CBall::Volume()const
{
double c;
c=pai*radius*radius*radius*4/3;
return c;
}
//圆柱类
class CCylinder: public CSolid
{
private:
double radius;
double height;
public:
CCylinder(double r=0,double high=0);
double SurfaceArea()const;
double Volume()const;
};
CCylinder::CCylinder(double r,double high)
{
radius=r;
height=high;
}
double CCylinder::SurfaceArea()const
{
double c;
c=2*pai*radius*radius+2*pai*radius*height;
return c;
}
double CCylinder::Volume()const
{
double c;
c=pai*radius*radius*height;
return c;
}

int main()
{
CSolid *p;
double s,v;
CCube x(30);
cout<<"正方体的边长是30"<<endl;
p=&x;
s=p->SurfaceArea();
v=p->Volume();
cout<<"表面积为："<<s<<endl;
cout<<"体积为："<<v<<endl;
cout<<endl;
CBall y(4.5);
cout<<"球体的半径为4.5"<<endl;
p=&y;
s=p->SurfaceArea();
v=p->Volume();
cout<<"表面积："<<s<<endl;
cout<<"体积："<<v<<endl;
cout<<endl;
CCylinder z(10,20);
cout<<"圆柱体底面半径，高分别为10,20"<<endl;
p=&z;
s=p->SurfaceArea();
v=p->Volume();
cout<<"表面积："<<s<<endl;
cout<<"体积："<<v<<endl;
cout<<endl;
return 0;
}