Question

C++ Chapters 3 and 4 discuss sorted and unsorted linear lists. In each of the text examples, the program begins with an empty list, data is added and manipulated, and the program ends freeing the data. Suggest ideas for dealing with list data that would have more permanence and be stored and retrieved as needed. Use code fragments to illustrate your response.

Answer 1

Program:-

music.txt:-

Imagine a text file music.txt with the followingcontent:

AC/DC,Dirty Deeds Done Dirt Cheap,303,
Alison Moyet,All Cried Out,410,
Allan Browne Quintet,Cyclosporin,291,
The Angels,Take A Long Line,180,

Output:-

Code to copy:-

#include "stdafx.h"

#include <iostream>

#include <fstream>

#include <string>

#include <vector>

#include <algorithm>

#include <iterator>

#include <sstream>

#include <set>

#define kMaxLineSize 2048

#define kMusicLibraryFileName "music.txt"

using namespace std;

struct song {

     string artist;

     string title;

     int duration;

};

class Playlist

{

     public:

     string clear()

     {

          playList.erase(playList.begin(), playList.end());

          return "Cleared play list";

     };

     string load(string fileName)

     {

          ifstream musicFile(fileName.c_str());

          if(!musicFile)

          {

              cout << "Can't open input file " << fileName << endl;

              exit(1);

          }

          while(!musicFile.eof())

          {

              // Read a line from file and split on commas

              string bufString;

              getline(musicFile, bufString);

              vector<string> tokens = tokenizer(bufString, ",");

              // Add song to library

              if(tokens.size() == 3) {

                   song newSong;

                   newSong.artist = tokens.at(0);

                   newSong.title = tokens.at(1);

                   newSong.duration = atoi(tokens.at(2).c_str());

                   playList.push_back(newSong);

              }

          }

         

          return "Loaded music data";

     }

     string info()

     {

          ostringstream ost;

          vector<song>::iterator i;

          for(i = playList.begin(); i != playList.end(); i++)

          {

              ost << (*i).artist << "," << (*i).title << "," << (*i).duration << "," << endl;

          }

          return ost.str();

     }

     string add()

     {

          // Roll you own song adding routine...

          song newSong;

          newSong.artist = "The Adders";

          newSong.title = "Adding at the end";

          newSong.duration = 120;

          playList.push_back(newSong);

          return "Added song";

     };

     string save(string fileName)

     {

          ofstream musicFile(fileName.c_str());

          if(!musicFile)

          {

              cout << "Can't open output file " << fileName << endl;

              exit(1);

          }

          musicFile << info();

          musicFile.close();

          return "Saved music data";

     };

     protected:

     vector<string> tokenizer(string s, string delimiter)

     {

          size_t start = 0;

          size_t end = s.find(delimiter);

          vector<string> tokens;

          while ( end != string::npos )

          {

              string token = s.substr(start, end-start);

              tokens.push_back(token);

              start = end+delimiter.size();

              end = s.find(delimiter, start);

          }

          return tokens;

     }

     private:

     vector<song> playList;

};

bool isCommand(string command, string in)

{

     return in.find(command,0) != string::npos;

}

int getCommandArgument(string s)

{

     int arg = -1;

     if(string::npos != s.find(" "))

     {

          arg = atoi(s.substr(s.find(" ")).c_str());

     }

     return arg;

}

int main ()

{

     cout << "Simulation MP3 player" << endl;

     Playlist masterList;

     string command;

     do

     {

          cout << endl << "Command (info, add, load, save, clear):";

          getline(cin, command);

          if(isCommand("info", command))

          {

              cout << masterList.info();

          }

          else if(isCommand("add", command))

          {

              cout << masterList.add();

          }

          else if(isCommand("load", command))

          {

              cout << masterList.load(kMusicLibraryFileName);

          }

          else if(isCommand("save", command))

          {

              cout << masterList.save(kMusicLibraryFileName);

          }

          else if(isCommand("clear", command))

          {

              cout << masterList.clear();

          }

          else if(isCommand("quit", command))

          {

              // No cleanup needed

          }

          else

          {

              cout << "Illegal command" << endl;

          }

     } while(!isCommand("quit", command));

     return 0;

     system("pause");

}

Answer 2

#include<iostream.h>

#incude<conio.h>

void main()

{

int n,a[15],i,j,temp;

clracr();

cout<<"enter how many element u want ";

cin>>n;

cout<<"enter the element\n";

for(i=0;i<n;i++)

cin>>a[i];

for(i=0;i<n;i++)

{

for(j=i;j<n-1;j++)

{

if(a[i]>a[j+1])

{

temp=a[i];

a[i]=a[j+1];

a[j+1]=temp;

}}}

cout<<"after sorting the given list of eements\n";

for(i=0;i<n;i++)

cout<<a[i]<<" ";

getch();

}