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aliklz92 (14)
Write your question here.
Hi,
Im tryin to write this code. The music library suppused to contain the following information for each song:
id (sequence of numbers and/or letters, without spaces)
title (may contain spaces in it)
artist (may contain spaces in it)
size (in Megabytes, could have fractional parts)
plays (number of times the song has been played, a whole number)
rating (a value between 1 and 5, the number of stars in the rating, a whole number)
and the output should be like :
Menu

1. Display Songs sorted by title
2. Display Songs sorted by rating
3. Lookup title and artist by ID
4. Lookup ID by title and artist
5. Quit the Program

Enter your choice: 1

Happy Pharrell Williams 3.9 MB 15 4
Let It Go Idina Menzel 4.8 MB 99 5
My Heart Will Go On Celine Dion 5.4 MB 9 5
You've Got a Friend in Me Randy Newman 4.2 MB 6 2

but im keep getting wierd things when i input my number here s my code:
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#include <iostream>
#include <fstream>
#include<string>

using namespace std;
struct music
{
	string id;
	string title;
	string artist;
	double s;
	int plays;
	int rating;
};
void print(struct music x) //function to print the details of a song
{
	cout << x.title << " " << x.artist << " " << x.s << " MB " << x.plays << " " << x.rating << " " << endl;
}
int main()
{
	ifstream fin;
	fin.open("library.txt");
	struct music a[100];
	int n = 0;
	while (n<100)
	{
		fin >> a[n].id;
		fin >> a[n].title;
		fin >> a[n].artist;
		fin >> a[n].s;
		fin >> a[n].plays;
		fin >> a[n].rating;
		if (a[n].id != "")
			n++;
		else
			break;
	}
	int ch, j, i, flag;
	ch = 0;
	string t, id, ar;
	while (ch != 5)
	{
		cout << "Menu" << endl << endl;
		cout << "1. Display songs sorted by title" << endl;
		cout << "2. Display songs sorted by rating" << endl;
		cout << "3. Lookup title and artist by id" << endl;
		cout << "4. Lookup id by title and artist" << endl;
		cout << "5. Quit the program" << endl;
		cout << "Enter your choice : ";
		cin >> ch;
		switch (ch)
		{
		case 1:
			for (i = 0;i<n - 1;i++)
			{
				for (j = 0;j<n - i - 1;j++)
				{
					if (a[j].title>a[j + 1].title) //sorting all the songs by title
					{
						struct music temp;
						temp = a[j];
						a[j] = a[j + 1];
						a[j + 1] = temp;
					}
				}
			}
			for (i = 0;i<n;i++)
			{
				print(a[i]);
			}
			break;
		case 2:
			for (i = 0;i<n - 1;i++)
			{
				for (j = 0;j<n - i - 1;j++)
				{
					if (a[j].rating>a[j + 1].rating) //sorting all the songs by rating
					{
						struct music temp;
						temp = a[j];
						a[j] = a[j + 1];
						a[j + 1] = temp;
					}
				}
			}
			for (i = 0;i<n;i++)
			{
				print(a[i]);
			}
			break;
		case 3:
			cout << "Enter id : ";
			cin >> id;
			flag = 0;
			for (j = 0;j<n;j++) //checking all the songs for input id and printing the required title and author
			{
				if (a[j].id == id)
				{
					cout << "The song with id " << id << " is " << a[j].title << " by " << a[j].artist << endl;
					flag = 1;
				}
			}
			if (flag == 0)
				cout << "Id not found!" << endl;
			break;
		case 4:
			cout << "Enter title : ";
			cin >> t;
			cout << "Enter artist : ";
			cin >> ar;
			flag = 0;
			for (j = 0;j<n;j++) //checking all the songs for input author and title and printing the required id
			{
				if (a[j].title == t && a[j].artist == ar)
				{
					cout << "The id of " << t << " by " << ar << " is " << a[j].id << endl;
					flag = 1;
				}
			}
			if (flag == 0)
				cout << "Artist and title not found!" << endl;
			break;
		case 5:
			cout << "Quitting!" << endl;
			break;
		default:
			cout << "Wrong Input!" << endl;
		}
	}
	system("pause");
	return 0;
}
salem c (3700)
> title (may contain spaces in it)
> artist (may contain spaces in it)
> ...
> Happy Pharrell Williams 3.9 MB 15 4
So how do you propose to tell the difference between
- a song titled "Happy Pharrell" by an artist called "Williams", and
- a song titled "Happy" by "Pharrell Williams"

Also, you need to start using functions.
Your main should look something like this.
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int main ( ) {
    vector<music> database;
    readData(database,"library.txt");
    do {
        displayMenu();
        choice = readChoice();
        switch ( choice ) {
            case 1:
                displaySongsByTitle(database);
                break;
            // ditto other cases, each is a 1-line call to a function.
        }
    } while ( choice != 5 );
}
aliklz92 (14)
Thank you, but the thing is we havent study vectors so i have no idea how to use that, and also im really confused how to fix the part you mentioned :(
salem c (3700)
> but the thing is we havent study vectors so i have no idea how to use that
You can still do the same thing with arrays.

Can you put library.txt on a share site. Something which actually preserves the internal format of the text file.


aliklz92 (14)
the library is:
A201
My Heart Will Go On
Celine Dion
5.4 9 5
B331
Happy
Pharrell Williams
3.9 15 4
D210
Let It Go
Idina Menzel
4.8 99 5
A122
You've Got a Friend in Me
Randy Newman
4.2 6 2
salem c (3700)
Right, that's a lot clearer.

Things like this.
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getline(fin,a.id);
getline(fin,a.title);
getline(fin,a.artist);
string temp
getline(fin,temp);
// parse temp into 's', 'plays', 'rating' members

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