十四周项目3

代码;

#include<iostream>
#define PI 3.1415926
using namespace std;
class CSolid{
public:
 virtual double area()=0;
 virtual double voumal()=0;
};
class CCube:public CSolid{
public:
   CCube(double x):x(x){}
   double area(){
   return x*x*6;
   }
  double voumal(){
    return x*x*x;
  }
private:
 double x;

};
class CBall:public CSolid{
public:
    CBall(double r):r(r){}
  double area(){

  return 4*PI*r*r;
  }
 double voumal(){
 return 4/3*PI*r*r*r;
 }

private:
double r;

};
class CCylinder:public CSolid{
public:
    CCylinder(double r,double h):r(r),h(h){}
    double area(){

    return PI*r*r*2+2*PI*r*h;
    }
  double voumal(){
  return PI*r*r*h;
  }

private:
    double r,h;

};
int main(){
   CSolid *p;
   CCube a(12);
   p=&a;
   cout<<"边长是12的正方体表面积是"<<p->area()<<endl;
   cout<<"边长是12的正方体体积是"<<p->voumal()<<endl;
   CBall b(4);
   p=&b;
   cout<<"半径是4的球体表面积是"<<p->area()<<endl;
   cout<<"半径是4的球方体体积是"<<p->voumal()<<endl;
   CCylinder c(2,3);
   p=&c;
   cout<<"底面半径是2，高是3的圆柱体表面积是"<<p->area()<<endl;
   cout<<"底面半径是2，高是3的圆柱体体积是"<<p->voumal()<<endl;

 

 

   return 0;
}

运行结果：