cin file input integers

[Spiffy P Mcgee]

here is my code:

#include <iostream>
#include <iomanip>
#include <cmath>
#include <fstream>
using namespace std;
int main()
{	
	ifstream inFile;
	double a, b, c;							
	double linroot;
	double quadroot1, quadroot2;			// resulting roots
	double discriminant;

	cout << showpoint << fixed << setprecision(2);
	cout << "COMPUTE THE REAL ROOT(S)";
	cout << "OF A QUADRATIC OR A LINEAR EQUATION\n\n";
	cin >> Filename;
	inFile.open();
	inFile >> a;
	inFile >> b;
	inFile >> c;
	while (a != -9999 && b != -9999 && c != -9999)
	{	
		discriminant =  b * b - (4 * a * c);
		if (a == 0 && b == 0)
		
			cout << "No linear or quadratic equation is formed.\n\n";			
		else if (discriminant < 0)
			cout << "Roots are not real.\n\n";
		else if (a == 0)
		{
			linroot = -1 * (c / b);
			cout << "Root is " << linroot << " .\n\n";
		}
		else 
		{
			quadroot1 = (-b + pow(discriminant, .5)) / (2 * a);
			quadroot2 = (-b - pow(discriminant, .5)) / (2 * a);
			cout << "Roots are " << quadroot1 << " and " << quadroot2 ;
		}	
	
			inFile >> a;
			inFile >> b;
			inFile >> c;
	}
	
	inFile.close ();
	cout << "Programmer: ";
	return 0;
		
	
}

It's supposed to calculate the zeros of a quadratic and linear equation. It generates error numbers 2605 and 2661. I'm still unclear about how to successfully get a file using cin. Help would be greatly appreciated. Thanks.

[hamsterman]

one error comes from line 18. open() needs some arguments. see http://www.cplusplus.com/reference/iostream/fstream/open/
I don't see the other one though. Which line is it form?
By the way, it would be good if you, in your future posts, would write more than the error code.

[Spiffy P Mcgee]

I have errors listed at 27 and 28. I confused about how to get the user to input a file . A lot of the file input/output material i've read has the file specified in the code. Next time I'll try to post more than error code. I just joined today because of this problem.

[Spiffy P Mcgee]

Okay I added this:

char Filename[20];

it's fixed. Do you always set that up? It seems odd to use the char data type.

[hamsterman]

Oh. well, if you need a variable, you have to declare it.
What's odd about char ? If you want you could (and probably should) use std::string though.

[Spiffy P Mcgee]

thanks for your help!