problem s ulohou v mistrovstvi c++

#include <iostream>
#include <cstring>
using namespace std;

class Cow                                         //delkaracia urcena v knihe
{
private:
   char name[20];
   char * hobby;
   double weight;
public:
   Cow();
   Cow(const char * nm, const char * ho, double wt);
   Cow(const Cow &c);
   ~Cow();
   Cow & operator=(const Cow & c);   
   void ShowCow();
};

Cow::Cow()
{
   strcpy(name, "Nezname");
   hobby = new char[9];
   strcpy(hobby, "Flakanie");
   weight = 0;
}

Cow::Cow(const char *nm, const char *ho, double wt)
{
   strcpy(name, nm);
   hobby = new char[strlen(ho)];
   strcpy(hobby, ho);
   weight = wt;
}

Cow::Cow(const Cow &c)
{
   strcpy(name, c.name);
   hobby = new char[strlen(c.hobby)];
   strcpy(hobby, c.hobby);
   weight = c.weight;
}

Cow & Cow::operator =(const Cow &c)
{
   if(this == &c)
      return *this;
   strcpy(name, c.name);
   delete [] hobby;
   hobby = new char[strlen(c.hobby)];
   strcpy(hobby, c.hobby);
   weight = c.weight;
   return *this;
}

Cow::~Cow()
{
   delete [] hobby;
}

void Cow::ShowCow()
{
   cout << "Meno: " << name << endl;
   cout << "Hobby: " << hobby << endl;
   cout << "Vaha: " << weight << endl;
}

int main()
{
   Cow c1;
   Cow c2("Milka", "Futbal", 600);
   cout << "Vypis c1 a c2\n";
   c1.ShowCow();
   c2.ShowCow();
   cout << "Priradenie c2 do c1:\n";
   c1 = c2;
   cout << "C1 teraz:\n";
   c1.ShowCow();
   Cow c3("Etela", "Hokej", 650);
   Cow c4(c3);
   cout << "C4 inizializovane c3:\n";
   c4.ShowCow();
   cout << "Koniec.\n";
   cin.get();
   cin.get();
   return 0;
}

   hobby = new char[strlen(ho)];
   strcpy(hobby, ho);

   hobby = new char[strlen(ho)+1];    // vsade pridat +1 pre ukoncovaci nulovy znak

#ifndef COW_HPP_INCLUDED
#define COW_HPP_INCLUDED

class Cow {
    private:
        char name[20];
        char * hobby;
        double weight;

    public:
        Cow();
        Cow(const char * nm, const char * ho, double wt);
        Cow(const Cow & c);
        ~Cow();
        Cow & operator=(const Cow & c);
        void ShowCow() const;
};

#endif // COW_HPP_INCLUDED

#include "cow.hpp"
#include <iostream>
#include <cstring>

Cow::Cow()
{
    strcpy(name,"cow");
    hobby = new char[20];
    strcpy(hobby,"hobby");
    weight = 0;
}

Cow::Cow(const char * nm, const char * ho, double wt)
{
    strcpy(name,nm);
    hobby = new char[strlen(ho)+1];
    strcpy(hobby,ho);
    weight = wt;
}

Cow::Cow(const Cow & c)
{
    strcpy(name,c.name);
    hobby = new char[strlen(c.hobby) + 1];
    strcpy(hobby, c.hobby); // copy string to new location
    weight = c.weight;
}

Cow::~Cow()
{
    delete [] hobby;
}

Cow & Cow::operator=(const Cow & c)
{
    if (this == &c)           // object assigned to itself
        return *this;          // all done
    delete [] hobby;             // free old string
    strcpy(name,c.name);
    weight = c.weight;
    hobby = new char [strlen(c.hobby)+ 1];  // get space for new string
    strcpy(hobby, c.hobby);  // copy the string
    return *this;              // return reference to invoking object
}

void Cow::ShowCow() const
{
    std::cout<<"name: "<<name<<std::endl<<"hobby: "<<hobby<<std::endl<<"weight: "<<weight<<std::endl;
}

#include "cow.hpp"

int main()
{
    Cow cow, cow2("reDo","C++",200);
    cow.ShowCow();
    cow2.ShowCow();

    Cow newCow = cow2, newCow2;
    newCow.ShowCow();
    newCow2 = cow2;
    newCow2.ShowCow();

    return 0;
}