Metoda eliminării succesive (Metoda Gauss) - rezolvarea sistemului de N ecuații cu N necunoscute

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

void Citire(float a[][10], int& n)
{
    ifstream f("matrice.in");
    f >> n;

    for (int i = 0; i < n; i++)
        for (int j = 0; j <= n; j++)
            f >> a[i][j];
}

void Zero(float& x)
{
    if (x == -0)
        x = 0;
}

void Afisare(float a[][10], int n)
{
    for (int i = 0; i < n; i++, cout << "\n")
        for (int j = 0; j <= n; j++)
        {
            Zero(a[i][j]);
            cout << setw(10) << a[i][j];
        }
}
void Pivotare(float a[][10], int n)
{
    for (int i = 0; i < n; i++)
        for (int k = i + 1; k < n; k++)
            if (fabs(a[i][i]) < fabs(a[k][i]))
                for (int j = 0; j <= n; j++)
                    swap(a[i][j], a[k][j]);
}

void Eliminare(float a[][10], int n)
{
    for (int i = 0; i < n - 1; i++)
        for (int k = i + 1; k < n; k++)
        {
            float t = a[k][i] / a[i][i];
            for (int j = 0; j <= n; j++)
            {
                a[k][j] = a[k][j] - t * a[i][j];
                Zero(a[k][j]);
            }
        }
}

void Solutie(float a[][10], int n, float x[])
{
    char variabila = 'a';
    for (int i = n - 1; i >= 0; i--)
    {
        x[i] = a[i][n];
        for (int j = i + 1; j < n; j++)
            if (j != i)
                x[i] = x[i] - a[i][j] * x[j];
        x[i] = x[i] / a[i][i];
        Zero(x[i]);
    }

    cout << "\nValorile variabilelor: \n";
    for (int i = 0; i < n; i++)
    {
        cout << (char)(variabila + i) << " = ";
        cout << x[i] << endl;
    }
}

int main()
{
    int n;
    float a[10][10] = { 0 }, x[10] = { 0 };
    char variabila = 'a';

    cout.precision(4);
    cout.setf(ios::fixed);

    Citire(a, n);

    Pivotare(a, n);
    cout << "Matricea extinsa dupa pivotare: \n";
    Afisare(a, n);

    Eliminare(a, n);
    cout << "\n\nMatricea extinsa dupa aplicarea metodei eliminarii: \n";
    Afisare(a, n);

    Solutie(a, n, x);
    return 0;
}