【13.2】c++ primer plus 课后编程答案

/*user.h*/
#ifndef USERSH_H_
#define USERSH_H_
#include <string>
using std::ostream;
using std::istream;
using std::string;

class Cd
{
private:
char * performers;
char * lable;
int selections;
double playtime;
public:
Cd(char * s1, char * s2, int n, double x);
Cd(const Cd & d);
Cd();
virtual ~Cd(){delete [] performers; delete [] lable;}
virtual void Report() const;
Cd & operator = (const Cd & d);
};

class Classic : public Cd
{
private:
char * works;
public:
Classic(char * s3, char * s1, char * s2, int n, double x);
Classic(char * s3, const Cd & d);
Classic(const Classic & c);
Classic();
~Classic(){delete works;}
virtual void Report() const;
Classic & operator = (const Classic & c);
};
#endif

/*userfucntion.cpp*/
#include "usersh.h"
#include <iostream>
#include <cstring>
using std::cout;
using std::cin;
using std::endl;
using std::string;
using std::ostream;
using std::istream;

Cd::Cd()
{
performers = new char [1];
performers[0] = '\0';
lable = new char [1];
lable = '\0';
selections = 0;
playtime = 0.0;
}

Cd::Cd(char * s1, char * s2, int n, double x)
{
performers = new char [strlen(s1)+1];
strcpy(performers, s1);
lable = new char [strlen(s2)+1];
strcpy(lable, s2);
selections = n;
playtime = x;
}

Cd::Cd(const Cd & d)
{
performers = new char [strlen(d.performers)+1];
lable = new char [strlen(d.lable)+1];
strcpy(performers, d.performers);
strcpy(lable, d.lable);
selections = d.selections;
playtime = d.playtime;
}

Cd & Cd::operator =(const Cd & d)
{
if (this == &d)
return *this;
delete [] performers;
delete [] lable;
performers = new char [strlen(d.performers)+1];
lable = new char [strlen(d.lable)+1];
strcpy(performers, d.performers);
strcpy(lable, d.lable);
selections = d.selections;
playtime = d.playtime;
return * this;
}

void Cd::Report() const
{
cout << "Performers: " << performers << endl;
cout << "Lable :" << lable << endl;
cout << "Selections: " << selections << endl;
cout << "Playtime: " << playtime << endl;
}

Classic::Classic(char * s3, char * s1, char * s2, int n, double x)
:Cd(s1,s2,n,x)
{
works = new char [strlen(s3)+1];
strcpy(works, s3);
}

Classic::Classic(char * s3, const Cd & d)
:Cd(d)
{
works = new char [strlen(s3)+1];
strcpy(works, s3);
}

Classic::Classic(const Classic & c)
:Cd(c)
{
works = new char [strlen(c.works)+1];
strcpy(works, c.works);
}

Classic::Classic()
:Cd()
{
works = new char [1];
works[0] = '\0';
}
Classic & Classic::operator =(const Classic & c)
{
if(this == &c)
return *this;
Cd::operator =(c);
delete [] works;
works = new char [strlen(c.works)+1];
strcpy(works, c.works);
}

void Classic::Report() const
{
Cd::Report();
cout << "Works: " << works <<endl;
}

/*main*/
#include <iostream>
#include <Windows.h>
#include "usersh.h"

using std::cout;
using std::cin;
using std::endl;
void Bravo(const Cd & disk);

int main()
{
Cd C1("Beat", "Captiol", 14, 35.5);
Classic C2=Classic("Piano In B Flat, Fants in C ",
"Alfread Bren", "Phillips", 2, 57.17);
Cd *pcd = &C1;
cout << "Use obj dirc: \n";
C1.Report();
C2.Report();

cout << "Use *pcd to obj:\n";
pcd->Report();
pcd = &C2;
pcd->Report();

cout << "Calling A function :\n";
Bravo(C1);
Bravo(C2);

cout << "Testing :\n";
Classic copy;
copy = C2;
copy.Report();

system("pause");
return 0;
}

void Bravo(const Cd & disk)
{
disk.Report();
}