dzialania na macierzach

#include <iostream>
#include <fstream>
#include <cstdlib>
#include <iomanip>

//Andrzej Porebski gr2 imim
//dzialania na macierzach

using namespace std;

float tab [3][3];

void suma()
{
    float k = tab[0][0] + tab [1][1] + tab [2][2];
    cout << k << endl;
}

void iloczynskalar()
{
    cout << "iloczyn macierzy przez skalar ma postac: " << endl << endl;
    for (int g = 0; g <= 3; g++)
    {
        for (int h = 0; h <= 3; h++)
        {
            float l = tab[g][h] * skalar;
            cout << setw(5) << l;
        }
        cout << endl;
    }
}

void iloczynsama()
{
    float w = tab[0][0]
    cout << "iloczyn macierzy przez sama siebie wynosi: " << endl << endl;
    for (int x = 0; x <= 3; x++)
    {
        for (int y = 0; y <= 3; y++)
        {
            float iloczynxyz[x][y] = 0;
            for (int z = 0; z <= 3; z++)
            {
                iloczynxyz[x][y] += tab[x][y] * tab[x][y];
            }
            cout << setw(5) << iloczynxyz[x][y];
        }
        cout << endl;
    }
}

int main()
{
    fstream dane ("plik.txt", ios::in);
    float skalar;
    cout << "Podaj liczbe do iloczynu: ";
    cin >> skalar;
    if (dane.good() == false)
    {
        cout << "problem z plikiem!" << endl;
        exit (0);
    }

    else
    {
        cout << "wczytana macierz ma postac: " << endl << endl;
        for (int i = 0; i < 3; i++)
        {
            for (int j = 0; j < 3; j++)
            {
                dane >> tab[i][j];
                cout << setw(5)<< tab [i][j];
            }
            cout << endl << endl;
        }
    }

    dane.close();

    cout << "suma na diagonali wynosi: ";
    suma();

    iloczynskalar();

    iloczynsama();

    return 0;
}