#4

#include <iostream>
#include <stdlib.h>         //rand(), srand()
#include <time.h>           //time() for srand()
#include <math.h>           //sqrt()
#include <sstream>          //for convert double to string. std::ostringstream
#define PI 3.1415926
using namespace std;

class figure {
public:
    virtual double V()=0;
    virtual double S()=0;
    virtual void scale(double)=0;
    friend ostream& operator<<(ostream&,const figure&);
//protected:
    virtual string show() const = 0;
};
ostream& operator<<(ostream& out, const figure&A) {
    out<<A.show();
    return out;
}

class ball: public figure {
private:
    double r;
    string show() const {std::ostringstream ost; ost<<r;  return "object Ball:     r="+ost.str();}
public:
    ball(double R=1.0): r(R) {}
    double V() {return 4*PI/3*r*r*r;}
    double S() {return 4*PI*r*r;}
    void scale(double k) {r*=k;}
};

class cone: public figure {
private:
    double r,h;
    string show() const {std::ostringstream ost1,ost2; ost1<<r; ost2<<h;  return "object Cone:     r="+ost1.str()+"\th="+ost2.str();}
public:
    cone(double R=1.0, double H=1.0): r(R), h(H) {}
    double V() {return PI*r*r*h/3;}
    double S() {return PI*r*(r+sqrt(r*r+h*h));}
    void scale(double k) {r*=k; h*=k;}
};

class cylinder: public figure {
private:
    double r,h;
    string show() const {std::ostringstream ost1,ost2; ost1<<r; ost2<<h;  return "object Cylinder: r="+ost1.str()+"\th="+ost2.str();}
public:
    cylinder(double R=1.0, double H=1.0): r(R), h(H) {}
    double V() {return PI*r*r*h;}
    double S() {return 2*PI*r*(r+h);}
    void scale(double k) {r*=k; h*=k;}
};

figure* createObject(int x, double r=1.0, double h=1.0) {
    figure* p = NULL;
    switch(x) {
    case 0: p = new ball(r); break;
    case 1: p = new cone(r,h); break;
    case 2: p = new cylinder(r,h); break;
    }
    return p;
}

int main() {
    srand(time(NULL));
    const int N=5;
    figure *arr[N];
    cout<<"Create objects:"<<endl;
    for(int i=0; i<N; i++) {
        arr[i]=createObject(rand()%3,(rand()%9999)/100.0,(rand()%9999)/100.0);
        cout<<*arr[i]<<endl<<"Square: "<<arr[i]->S()<<"\tVolume: "<<arr[i]->V()<<endl<<endl;
    }
    cout<<endl<<"After scaling:"<<endl<<endl<<endl;
    for(int i=0; i<N; i++) {
        arr[i]->scale(0.1);
        cout<<*arr[i]<<endl<<"Square: "<<arr[i]->S()<<"\tVolume: "<<arr[i]->V()<<endl<<endl;
    }
}