#include <iostream>
#include <cmath>

#define N 3

using namespace std;

class Figure {
    protected:
        double r;

        double v;

    public:
        void show() {
            cout << "Info about figure:" << endl;
            calculate();
            info();
        }

        virtual void info() = 0;

        virtual double calculate() = 0;
};

class Sphere : public Figure {
    public:
        Sphere() {r = v = 0;}

        Sphere(double _r) {r = _r;}

        void info() {
            cout << "Info about sphere:" << endl;
            cout << " r = " << r << endl << endl;
        }

        double calculate() {
            v = (4. / 3) * M_PI * pow(r, 3);
            cout << "Volume of sphere = " << v << endl << endl;

            return v;
        }

        friend istream& operator >> (istream& is, Sphere& x);

        bool operator <= (const Sphere& x) {return r <= x.r;}
};

class Cylinder : public Figure {
    private:
        double h;

    public:
        Cylinder() {r = h = v = 0;}

        Cylinder(double _r, double _h) {
            r = _r;
            h = _h;
        }

        void info() {
            cout << "Info about cylinder:" << endl;
            cout << " r = " << r << endl;
            cout << " h = " << h << endl << endl;
        }

        double calculate() {
            v = h * M_PI * pow(r, 2);
            cout << "Volume of сylinder = " << v << endl << endl;

            return v;
        }

        friend istream& operator >> (istream& is, Cylinder& x);

        bool operator <= (const Cylinder& x) {return r <= x.r && h <= x.h;}
};

istream& operator >> (istream& is, Sphere& x) {
    cout << "Enter info about sphere:" << endl;
    cout << " r = "; is >> x.r;
    cout << endl;

    return is;
}

istream& operator >> (istream& is, Cylinder& x) {
    cout << "Enter info about cylinder:" << endl;
    cout << " r = "; is >> x.r;
    cout << " h = "; is >> x.h;
    cout << endl;

    return is;
}

int main() {

    string res;
    Sphere spheres[N];
    Cylinder cylinders[N];

    cout << "Enter " << N << " spheres:" << endl << endl;

    for (int i = 0; i < N; i++) {
        cout << "Enter info about " << i + 1 << " sphere:" << endl;
        cin >> spheres[i];
    }

    cout << "Comparing:" << endl << endl;

    for (int i = 1; i < N; i++) {
        res = "false";
        cout << i << " sphere <= " << i + 1 << " sphere" << endl;

        if (spheres[i - 1] <= spheres[i]) res = "true";

        cout << "result: " << res << endl;
        cout << endl;
    }

    cout << endl;

    cout << "Enter " << N << " cylinders:" << endl << endl;

    for (int i = 0; i < N; i++) {
        cout << "Enter info about " << i + 1 << " cylinder:" << endl;
        cin >> cylinders[i];
    }

    cout << "Comparing:" << endl << endl;

    for (int i = 1; i < N; i++) {
        res = "false";
        cout << i << " cylinder <= " << i + 1 << " cylinder" << endl;

        if (cylinders[i - 1] <= cylinders[i]) res = "true";

        cout << "result: " << res << endl;
        cout << endl;
    }

    cout << endl;

    cout << "Pointer using base class:" << endl << endl;

    Figure* figr;

    figr = new Sphere(3);

    figr->show();

    figr = new Cylinder(3, 2);

    figr->show();

    delete figr;

    return 0;
}