Gauss Jordan Method in C/C++

PROGRAM :

/*To write a C/C++ program to find the solution of
the system of linear equations using Gauss Jordan
Method.*/

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
    int n,i,j,k;
    cout<<"\nEnter the no. of equations\n";        
    cin>>n;
    double a[n][n+1],x[n];
    cout<<"\nEnter the elements of the augmented-matrix row-wise:\n";
    for (i=0;i<n;i++)
        for (j=0;j<=n;j++)    
            cin>>a[i][j];
    for (i = 0; i < n; i++)
    {
        for (j = 0; j < n+1; j++)
            if (j != i)
            {
                double d = a[j][i] / a[i][i];
                for (k = 0; k < n+1; k++)
                    a[j][k] -= a[i][k] * d;
            }
    }
    cout<<"\n\nThe matrix after gauss-jordan elimination is as follows:\n";
    for (i=0;i<n;i++)
    {
        for (j=0;j<=n;j++)
            printf("%4f\t",a[i][j]);
printf("\n");
    }
    for(i=1;i<n;i++)
    {
    for (j=0;j<i;j++)
    {
    a[i][j]=0;
}
}
    for (i=n-1;i>=0;i--)
    {
x[i]=a[i][n];
for (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];
    }
    
    cout<<"\nThe values of the variables are as follows:\n";
    
    for (i=0;i<n;i++){
        cout<<(x[i])<<endl;
}
    return 0;
}

OUTPUT :

Enter the no. of equations
4

Enter the elements of the augmented-matrix row-wise:
10 -7 3 5 6
-6 8 -1 -4 5
3 1 4 11 2
5 -9 -2 4 7


The matrix after gauss-jordan elimination is as follows:
10.000000    0.000000    0.000000    0.000000    50.000000
0.000000     3.800000    0.000000    0.000000    15.200000
0.000000     0.000000    2.447368    0.000000   -17.131579
0.000000     0.000000    0.000000    9.924731     9.924731

The values of the variables are as follows:
5
4
-7
1