// This program demonstrates the passing of a file stream variable to a function.  Notice
// the use of the & symbol in the function prototype and heading.  You need this symbol as
// placed.	This program also finds the average of each row of 10 numbers from an input
// file and outputs the numbers and their averages to an output file.  An input file for this
// program should have some number of lines with each line containing 10 integers.

#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;

int openInput(ifstream& fin);

int main()
{

	ofstream fout;
	ifstream fin;
	char stuff[40];  // used to pick up whitespace at end of line
	int i, total = 0, x;
	const int sizeOfData = 10;  // the number of values being averaged

	if (openInput(fin) == 1)// input file not opened
		return 0;			// stop the program

	fout.open("output.txt");
	fout << fixed << showpoint << setprecision(1);

	while (!fin.eof())
	{
		fout << " Data in: ";
		for (i = 0; i < sizeOfData; i ++)	//sum the ten numbers in the row
		{
			fin>>x;
			fout << setw(3)<< x << ", " ;
			total += x;
		}
		// write out the average for that row
		fout << ": Average = " << setw(4)<< (double)total / sizeOfData << endl << endl;
		// reset total for use in next iteration -- easy to forget!!!
		total = 0;

		// check for blank spaces at end of line and throw them away
		
		fin.getline(stuff,40,'\n');
		
	}
	return 0;
}

// Function openInput will try to open a user specified input file, checking
// for success.  A return value of 1 indicates the file was not opened while
// a return value of 0 indicates the file was opened successfully.
int openInput(ifstream& fin)
{
	char fname[40];
	int bad = 1, good = 0;

	cout << "Please enter name of input file: " ;
	cin >> fname;
	fin.open(fname);
	if (!fin)
	{
		cout << " Could not open input file. " << endl;
		return bad;
	}
	else return good;	// open was successful
}