C++ fstream building but not running - c++

Question

I'm building a program for my class the requires us to import data from a .txt file and the item names/ prices will be used to calculate saltes tax and grand total. My teacher put this up as an example, but I can't get it to run.
#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
using namespace std;
int main()
{ // Beginning of main function
string name;
ifstream data_in;
ofstream data_out;
int cnt=0;
int number;
struct Item
{
int item_n;
char disc[50];
float price;
};
Item store[999];
data_in.open("cost.txt");
data_out.open("file_out.txt");
while(!data_in.eof())
{
//cout << "Enter in the item number: ";
data_in >> store[cnt].item_n;
//cout << "Enter in the description for item number " << store[cnt].item_n << ": ";
data_in >> store[cnt].disc;
//cout << "Enter in the price for the " << store[cnt].disc << ": $";
data_in >> store[cnt].price;
cnt++;
}
cout << endl << endl;
number = cnt;
for (cnt=0; cnt<number; cnt++)
{
name = store[cnt].disc;
cout << setw(5) << store[cnt].item_n << " " << store[cnt].disc << setw(16-name.length()) << "$" << setw(9) << store[cnt].price << endl;
}
for (cnt=0; cnt<number; cnt++)
{
name = store[cnt].disc;
data_out << setw(5) << store[cnt].item_n << " " << store[cnt].disc << setw(16-name.length()) << "$" << setw(9) << store[cnt].price << endl;
}
return 0;
}
And this is the information in the cost.txt file
Books 45.01
Pens 21.03
Pencils 10.90
Hats 50.00
Caps 800.00
Food 1.00

Answer 1

The code you've written reads three things for each Item: the item number, the description, and price.
The sample data file you shown contains only two things for each item: what looks to be a description, and a price.
The expected data format does not match the contents of the input file. This code will never work, as is. One or the other is wrong. Plus all the other problems with the code, as mentioned in the comments.

Answer 2

Try the following changes, the rest of your code seems to work:
data_in.open("cost.txt");
data_out.open("file_out.txt");
if (!data_in.is_open() || !data_out.is_open()) //Test if files opened correctly...
{
cout << "Failed to open a file!\n";
return 1;
}
float SalesTotal = 0;
while(true)
{
if (!(data_in >> store[cnt].disc))
{
//Failed to read first element in this record - could be eof or format error
if (data_in.eof())
break; //eof - all records read.
cout << "Format error first field\n";
return 1; //format error on first field.
}
if (!(data_in >> store[cnt].price))
{
cout << "Format error second field\n";
return 2; //format error on second field.
}
store[cnt].item_n = cnt + 1; //Item number is not a field in your file, use the counter...
SalesTotal += store[cnt].price;
cnt++;
}
if (!cnt)
{
cout << "No records read\n";
return 3; //No valid records read.
}
float GrandTotal = ((SalesTotal / 100) * 6) + SalesTotal;
cout << "Sales total: " << SalesTotal << " Grand total:" << GrandTotal << "\n";