OOP Labs 7 Zicani instrumenti

#include <iostream>
#include <cstring>

using namespace std;

class ZicanInstrument {
    private:
        char name[20];
        int noStrings;
        float price;
    public:
        ZicanInstrument();
        ZicanInstrument(const char * ime, const int brojZici, const float cena);
        ~ZicanInstrument();
        bool operator==(const ZicanInstrument *orig);
        virtual float cena();
};

ZicanInstrument::ZicanInstrument(){
    strcpy(this->name, "None");
    this->noStrings = 0;
    this->price = 0.0;
}
ZicanInstrument::ZicanInstrument(const char * ime, const int brojZici, const float cena){
    strcpy(this->name, ime);
    this->noStrings = brojZici;
    this->price = cena;
}
ZicanInstrument::~ZicanInstrument(){}
bool ZicanInstrument::operator==(const ZicanInstrument *orig){
    if(this->noStrings == orig->noStrings)
        return true;
    else
        return false;
}
float ZicanInstrument::cena(){
    return this->price;
}

//Mandolina
class Mandolina : public ZicanInstrument {
    private:
        char shape[20];
    public:
        Mandolina();
        Mandolina(const char * ime, const int brojZici, const float cena, const char * forma) : ZicanInstrument(ime, brojZici, cena){
            strcpy(this->shape, forma);
        }
        ~Mandolina();
        float cena();
};

Mandolina::Mandolina(){
    strcpy(this->shape, "N/A");
}
Mandolina::~Mandolina(){}
float Mandolina::cena(){
    if(!strcmp(this->shape, "Neapolitan"))
        return ZicanInstrument::cena() + ZicanInstrument::cena() * 0.15;
    else return ZicanInstrument::cena();
}

//Violina
class Violina : public ZicanInstrument{
    private:
        double size;
    public:
        Violina();
        Violina(const char * ime, const int brojZici, const float cena, const float golemina) : ZicanInstrument(ime, brojZici, cena){
            this->size = golemina;
        }
        ~Violina();
        float cena();
};

Violina::Violina(){
    this->size = 0.0;
}
Violina::~Violina(){}
float Violina::cena(){
    if(this->size == 0.25)
        return ZicanInstrument::cena() + ZicanInstrument::cena() * 0.1;
    else if(this->size == 1.00)
        return ZicanInstrument::cena() + ZicanInstrument::cena() * 0.2;
    else
        return ZicanInstrument::cena();
}

//global function
void pecatiInstrumenti(ZicanInstrument &zi, ZicanInstrument **x, int n){
    for(int i=0; i<n; i++){
        if(zi == x[i])
            cout << x[i]->cena() << endl;
    }
}

//main
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;
}