Question

C++

MAIN remains same

Given the complete main() function, partial playlist class header playlist.h, and playlist.cpp, you will complete the class declaration and class implementation. The following member functions are required:

• constructor
• copy constructor
• destructor
• addSong(song tune)
  • adds a single node to the front of the linked list
  • no return value
• displayList()
  • displays the linked list as formatted in the example below
  • no return value
• overloaded assignment operator

A description of all of these functions is available in the textbook's chapter 16 (which you should have already studied).

NOTE: Your linked list class should NOT be templated.

Example: If the input is:

3
Linda Ronstadt
You're no good
2.30
Rock
Elton John
Rocket Man
4.41
Rock
Antonin Leopold Dvorak
Songs my mother taught me
2.24
Classical

where 3 is the number of songs, and each subsequent four lines is an (artist, title, length, genre) record, the output is:

Antonin Leopold Dvorak, Songs my mother taught me, 2.24, Classical
Elton John, Rocket Man, 4.41, Rock
Linda Ronstadt, You're no good, 2.3, Rock

_______________________________________________

#include <iostream>
#include <string>
#include "playlist.h"
using namespace std;

int main()
{
song tune;
string genre;
playlist mySongs;
int num = 0;

cin >> num >> ws;
for (int i=0; i<num; i++)
{
   getline(cin, tune.artist);
   getline(cin, tune.title);
   cin >> tune.length >> ws;
   getline(cin, genre);
   if (genre == "Rock")
   tune.genre = genre_t::ROCK;
   else if (genre == "Country")
   tune.genre = genre_t::COUNTRY;
   else if (genre == "Pop")
   tune.genre = genre_t::POP;
   else if (genre == "Classical")
   tune.genre = genre_t::CLASSICAL;
   else
   tune.genre = genre_t::POLKA;

   mySongs.addSong(tune);
}

mySongs.displayList();

return 0;
}

________________________________________________

#ifndef PLAYLIST_H
#define PLAYLIST_H

#include <iostream>
#include <string>

enum class genre_t {ROCK, COUNTRY, POP, CLASSICAL, POLKA};

struct song
{
std::string artist;
std::string title;
float length;
genre_t genre;
song* next;
};

class playlist
{
public:

// TODO: add the required member functions and operator

private:
song* head;
};

#endif
_________________________________________________________________

#include "playlist.h"

// TODO: implement the class member functions and overloaded operator

Answer 1

Program

playlist.h

#ifndef PLAYLIST_H
#define PLAYLIST_H

#include <iostream>
#include <string>

enum class genre_t { ROCK, COUNTRY, POP, CLASSICAL, POLKA };

struct song
{
   std::string artist;
   std::string title;
   float length;
   genre_t genre;
   song* next;
};

class playlist
{
public:
   //Default constructor
   playlist();
   //Copy constructor
   playlist(playlist& p);
   //Destructor
   ~playlist();
   //Add a new song at the front of the list
   void addSong(song tune);
   //Display play list
   void displayList();
   //Assignment operator overload
   void operator=(playlist& p);
private:
   song* head;
};

#endif

playlist.cpp

#include "playlist.h"
//Default constructor
playlist::playlist() {
   head = NULL;
}
//Copy constructor
playlist::playlist(playlist& p) {
   if (p.head == NULL)
       head = NULL;

   else
   {
       song* temp = head;
       while (p.head != NULL) {
           temp = p.head;
           p.head = p.head->next;
           temp = temp->next;
       }
   }
}
//Destructor
playlist::~playlist() {
   delete head;
}
//Add a new song at the front of the list
void playlist::addSong(song tune) {
   if (head == NULL) {
       head = &tune;
       return;
   }
   else {
       tune.next = head;
       head = &tune;
       return;
   }
}
//Display play list
void playlist::displayList() {
   song* temp = head;
   while (temp != NULL) {
       std::cout << temp->artist << ", " << temp->title << ", " << temp->length << ", ";
       if (temp->genre == genre_t::ROCK)
           std::cout << "Rock\n";
       else if (temp->genre == genre_t::COUNTRY)
           std::cout << "Country\n";
       else if (temp->genre == genre_t::POP)
           std::cout << "Pop\n";
       else if (temp->genre == genre_t::CLASSICAL)
           std::cout << "Classical\n";
       else
           std::cout << "Polka\n";
       temp = temp->next;
   }
}
//Assignment operator overload
void playlist::operator=(playlist& p) {
   if (p.head == NULL)
       head = NULL;

   else
   {
       song* temp = head;
       while (p.head != NULL) {
           temp = p.head;
           p.head = p.head->next;
           temp = temp->next;
       }
   }
}

Output

3
Linda Ronstadt
You're no good
2.30
Rock
Elton John
Rocket Man
4.41
Rock
Antonin Leopold Dvorak
Songs my mother taught me
2.24
Classical
Antonin Leopold Dvorak, Songs my mother taught me, 2.24, Classical
Elton John, Rocket Man, 4.41, Rock
Linda Ronstadt, You're no good, 2.3, Rock

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