12.1

#include "cow.h"#include 
      
       #include 
       
        using std::cout;using std::endl;Cow::Cow(){    name[0] = '\0';    hobby = new char[1];    hobby[0] = '\0';    weight = 0.0;}Cow::Cow(const char * nm, const char * ho, double wt): weight(wt){    strcpy(name, nm);    hobby = new char[strlen(ho) + 1];    strcpy(hobby, ho);}Cow::~Cow(){    delete [] hobby;}// copy constructorCow::Cow(const Cow &c){    strcpy(name, c.name);    hobby = new char[strlen(hobby)+1];    strcpy(hobby, c.hobby);    weight = c.weight;}Cow & Cow::operator=(const Cow & c){    if(this == &c)        return *this;    delete [] hobby;    strcpy(name, c.name);    hobby = new char[strlen(c.hobby)+1];    strcpy(hobby, c.hobby);    return *this;}void Cow::ShowCow() const{    cout << "Name: " << name << '\t' << "Hobby: " << hobby << '\t';    cout << "Weight: " << weight << endl;}