c++ 6.14

#include<iostream>using namespace std;const double b=3.14;class base{public:base(double h1){ h=h1;}virtual void disp()=0;protected:double h;};class cuboid:public base{public:cuboid(double h1,double w1,double k1):base(h1){w=w1;    k=k1;}void disp(){cout<<"长方体的体积:"<<h*w*k<<endl;}protected:double w;double k;};class cylinder:public base{public:cylinder(double r1,double h1):base(h1){r=r1;}void disp(){cout<<"圆柱体的体积:"<<r*r*h*b<<endl;}protected: double r;};int main (){base *ptr;cuboid c1(2.1,3.1,4.0);cylinder l1(3.3,4.2);ptr=&c1;ptr->disp();cout<<"*************************"<<endl;ptr=&l1;ptr->disp();return 0;}