#include <iostream>
#include <string>
#include <vector>

using namespace std;

class FormaGeometrica{
  public:
    virtual ~FormaGeometrica() {}
    virtual float perimetro() const = 0;
    virtual float area() const = 0;
    virtual string colore() const { return "blue"; }
    virtual void print() const = 0;
};

class Quadrato: public FormaGeometrica{
  public:
    Quadrato(){myLato=0;}
    Quadrato(float lato){myLato=lato;}
    virtual ~Quadrato(){}
    float lato() const {return myLato;}
    virtual float perimetro() const {return 4*myLato;}
    virtual float area() const {return myLato*myLato;}
    virtual void print() const {
      cout << "Quadrato l=" << lato() << " area " << area() << " colore " <<
        colore() << endl;
    }
  private:
    float myLato;
};

class Circonferenza: public FormaGeometrica{
  public:
    Circonferenza(){myRaggio=0;}
    Circonferenza(float r){myRaggio = r;}
    virtual ~Circonferenza(){}
    float raggio() const {return myRaggio;}
    virtual float perimetro() const {return 4*3.14*myRaggio;}
    virtual float area() const {return 3.14*myRaggio*myRaggio;}
    string colore() const { return "red"; }
    virtual void print() const {
      cout << "Circonferenza r=" << raggio() << " area " << area() << " colore "
        << colore() << endl;
    }
  private:
    float myRaggio;
};

void draw(FormaGeometrica* f) ;

class Schermo {
  public:
    Schermo() {
      numElementi_ = 0;
//elementi_ = FormaGeometrica[];
    }

    ~Schermo() {
      erase();
    }

    void add(const FormaGeometrica* fg){
      elementi_.push_back(fg);
    }

    void print() const {
      cout << "Schermo::print" << endl;
      for (vector<const FormaGeometrica*>::const_iterator fg=elementi_.begin();
           fg<elementi_.end(); ++fg) {
        (*fg)->print();
      }
    }

    void erase(){
      for (vector<const FormaGeometrica*>::const_iterator fg=elementi_.begin();
           fg<elementi_.end(); ++fg) {
        if (*fg) delete *fg;
      }
      elementi_.clear();
    }

    const vector<const FormaGeometrica*> elementi() const {
      return elementi_;
    }

    int numElementi() const {
      return elementi_.size();
    }

  private:
    int numElementi_;
    vector<const FormaGeometrica*> elementi_;
};

int main () {
  FormaGeometrica *q = new Quadrato(3.);
  FormaGeometrica *circ = new Circonferenza(3.);

  Schermo schermo;

  schermo.add(q);
  schermo.print();

  schermo.add(circ);
  schermo.print();

  schermo.erase();
  schermo.print();

  draw(q);
  draw(circ);

  Circonferenza c(66.);
  cout <<"La circonferenza ha raggio "<<c.raggio()<<" perimetro "<<c.perimetro()<<" e area "<<c.area()<<endl;

  //Errore: StaticType of (*q) is FG, not Q
  //cout <<"Il quadrato ha lato "<<(*q).lato()<<" perimetro "<<(*q).perimetro()<<" e area "<<(*q).area()<<endl;
  //Errore: StaticType of (*q) is FG, not Q
  //cout <<"Il quadrato ha lato "<<q->lato()<<" perimetro "<<q->perimetro()<<" e area "<<q->area()<<endl;

  delete q;
  delete circ;

}

void draw(FormaGeometrica* f) {
  cout << "perimetro " << f->perimetro() << " colore " << f->colore() << endl;
}