Zhicani Instrumenti polimorfizam

#include<iostream>
#include<cstring>

using namespace std;

class ZicanInstrument{
protected:
    char ime [20];
    int broj;
    int cena;
    public:
    ZicanInstrument(char*ime="", int broj = 0 , int cena = 0 ){
    strcpy(this->ime,ime);
        this->broj=broj;
        this->cena=cena;
    }
    ZicanInstrument(const ZicanInstrument &z)
    {
        strcpy(this->ime,z.ime);
        this->broj=z.broj;
        this->cena=z.cena;
    }
    virtual int Cena()=0;
    int getBroj(){return this->broj;}

};
bool operator==(ZicanInstrument &levo , ZicanInstrument &desno)
{
return levo.getBroj()==desno.getBroj();
}
class Mandolina : public ZicanInstrument
{
    private:
    char forma[20];
    public:
    Mandolina(char*ime="", int broj = 0 , int cena = 0 , char*forma=""):ZicanInstrument(ime,broj,cena){
    strcpy(this->forma,forma);
    }
    Mandolina(const Mandolina &m):ZicanInstrument(m){
    strcpy(this->forma,m.forma);
    }
    int Cena()
    {
        if(strcmp(forma,"Neapolitan")==0)
        {
        return cena+(cena*0.15);
        }
        else
            return cena;
    }
    friend ostream &operator <<(ostream &out , const Mandolina &m)
    {
    out<<m.ime<<" "<<m.broj<<" "<<m.cena<<" "<<m.forma<<" "<<endl;
        return out;
    }


};
class Violina : public ZicanInstrument{
private:
    float golemina;
    public:
    Violina(char*ime="", int broj = 0 , int cena = 0 ,float golemina = 0.0):ZicanInstrument(ime,broj,cena)
    {
        this->golemina=golemina;
    }
    Violina(const Violina &v) :ZicanInstrument (v)
    {
    this->golemina=v.golemina;
    }
    int Cena()
    {
        if(golemina==0.25)
        {
        return cena+(cena * 0.1);
        }
        else if(golemina==1){
        return cena+(cena *0.2);
        }
        return cena;
    }
        friend ostream &operator <<(ostream &out , const Violina &v)
    {
    out<<v.ime<<" "<<v.broj<<" "<<v.cena<<" "<<v.golemina<<" "<<endl;
        return out;
    }


};
void pecatiInstrumenti(ZicanInstrument &zi, ZicanInstrument **instrument, int n)
{

    for(int i = 0 ; i < n ; i++)
    {
        if(instrument[i]->getBroj()==zi.getBroj())
        {
        cout<<instrument[i]->Cena()<<endl;
        }
    }
}
int main() {
    char ime[20];
    int brojZici;
    float cena;
    char forma[20];
    cin >> ime >> brojZici >> cena >> forma;
    Mandolina m(ime, brojZici, cena, forma);
    int n;
    cin >> n;
    ZicanInstrument **zi = new ZicanInstrument*[2 * n];
    for(int i = 0; i < n; ++i) {
        cin >> ime >> brojZici >> cena >> forma;
        zi[i] = new Mandolina(ime, brojZici, cena, forma);
    }
    for(int i = 0; i < n; ++i) {
        float golemina;
        cin >> ime >> brojZici >> cena >> golemina;
        zi[n + i] = new Violina(ime, brojZici, cena, golemina);
    }
    pecatiInstrumenti(m, zi, 2 * n);
    for(int i = 0; i < 2 * n; ++i) {
        delete zi[i];
    }
    delete [] zi;
    return 0;
}