#include <fstream>
#include <string>
#include <stdlib.h>
#include <iostream>

using namespace std;

int fill_matrix(string filename, int *N, double **A)
{
    int n, i, j;
    double *a;

    ifstream fin(filename.c_str());

    if (!(fin >> n))
        return 2;

    a = (double *) malloc(n * n * sizeof(double) );

    if (a == NULL)
        return 2;

    for (i = 0; i < n; i++)
        for (j = 0; j < n; j++)
            if (!(fin >> a[i * n + j]))
            {
                free(a);
                return 5;
            }

    *N = n;
    *A = a;

    return 0;
}

int fill_vector(string filename, int *N, double **A)
{
    ifstream fin(filename.c_str());

    int n, i;
    double *a;

    if (!(fin >> n))
        return 2;

    a = (double *) malloc(n * sizeof(double));

    if (a == NULL)
        return 2;

    for (i = 0; i < n; i++)
        fin >> a[i];

    *N = n;
    *A = a;

    return 0;
}

void fill_matrix_formula(int n, double **A)
{
    int i, j;
    double *a;

    a = (double *) malloc(n * n * sizeof(double) );

    for (i = 0; i < n; i++)
        for (j = 0; j < n; j++)
            a[i * n + j] = 1.0/(i + j + 1.0);

    *A = a;
}

void output_matrix(string filename, int n, double *a)
{
    //ofstream fout(filename.c_str());

    int i, j;

    for (i = 0; i < n; i++)
    {
        for (j = 0; j < n; j++)
            cout << a[i * n + j] << " ";

        cout << endl;
    }
}

void output_vector(string filename, int n, double *a)
{
    //ofstream fout(filename.c_str());

    int i;

    cout << endl << "~~";

    for (i = 0; i < n; i++)
        cout << a[i] << " ";

}

int main()
{
    int n = 5;
    double *a;
    double *v;

    fill_matrix("input.txt", &n, &a);
    //fill_matrix_formula(n, &a);
    output_matrix("output.txt", n, a);
    fill_vector("input.txt", &n, &v);

    output_vector("output.txt", 5, v);

    cout << n;

}