Programming Error?

[maximus87]

When I try to run this code (see below), I get 4 lines of:
-1.#IND
-1.#IND
-1.#IND
-1.#IND

I am using VS Express 2013, but when my friend runs it in his VS Express 2010, it runs fine. Why is this happening?

// Naive_Gaussian.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
#include <cmath>

using namespace std;
void NaiveGaussian(int n, float a[4][4], float b[4], float x[4]);

void main()
{
	int nsize = 4;
	float aa[4][4] = { { 2, -1, 3, 7 }, { 4, 4, 0, 7 }, { 2, 1, 1, 3 }, { 6, 5, 4, 17 } };
	float bb[4] = { 15, 11, 7, 31 };
	float xx[4];

	NaiveGaussian(nsize, aa, bb, xx); // x is the solution
	cout << xx[0] << endl;
	cout << xx[1] << endl;
	cout << xx[2] << endl;
	cout << xx[3] << endl;

	cin.ignore();
}

void NaiveGaussian(int n, float a[4][4], float b[4], float x[4]) //paranthesis is the arguments
{
	int i, j, k;
	float sum, xmult;
	for (k = 0; k <= n - 2; k++)
	{
		for (i = k + 1; i <= n - 1; i++)
		{
			xmult = a[i][k] / a[k][k];
			a[i][k] = xmult;
			for (j = k + 1; j <= n - 1; j++)
			{
				a[i][j] = a[i][j] - xmult*a[k][j];
			}
			b[i] = b[i] - xmult*b[k];
		}
	}
	x[n - 1] = b[n - 1] / a[n - 1][n - 1];
	for (i = n - 2; i >= 0; i--)
	{
		sum = b[i];
		for (j = i + 1; j <= n - 1; j++)
		{
			sum = sum - a[i][j] * x[j];
		}
		x[i] = sum / a[i][i];
	}
}

[tipaye]

Check your data, you have a divide by zero poisoning the well (hint aa[1][2])

[maximus87]

I see the 0 that you are referring too, but I can't change that because that is part of the data. Unless i change it to 0.0001. But is there another way to fix it? There's also the other issue that this program can run just fine in VS Express 2010. Any reason why that is?