Inheritance & Polymorphism

/*This code was written by A. El-Gadi of Tripoli University for educational purposes. The code illustrates inheritance and polymorphism in C++. It uses a necklace with several types of beads as an example. For any questions use the comment section below.*/

#include <iostream>
#include <cmath>
#include <stdlib.h>
using namespace std;

class Bead{
    protected:
    const double density;
    public:
    virtual double weight()=0;
    virtual void show(){cout<<"-B";}
    Bead(double D):density(D){};
    virtual ~Bead(){};
    };

class SBead:public Bead{
    private:
    double r;//radius
    public:
    double weight(){return (4/3*3.14159*r*r*r*density);}
    void show(){cout<<"-S";}
    void setR(double R){r=R;}
    SBead(double R,double D):r(R),Bead(D){};
    };

class CBead:public Bead{
        private:
        double s;//side length
        public:
        double weight(){return s*s;}
        void show(){cout<<"-C";}
        void setS(double S){s=S;};
        CBead(double S,double D):s(S),Bead(D){};
        };

class CyBead:public Bead{
        private:
        double r;//radius
        double h;//height
        public:
        double weight(){return r*r*h*3.14159;}
        void show(){cout<<"-Z";}
        void setRH(double R, double H){r=R;h=H;};

        CyBead(double R,double H, double D):r(R),h(H),Bead(D){};
        };

int main(){
Bead *bds[25];Bead *b;

for(int i=0;i<25;i++){
switch (rand()%3){
case 0: bds[i]=new  SBead(10,1.5); break;
case 1: bds[i]=new  CBead(10,1.5); break;
case 2: bds[i]=new  CyBead(10,5,1.5);}
}

for(int i=0;i<25;i++){bds[i]->show();}

return 0;
}