Dev - C++ - aumentar escala de una matriz

#include <iostream>

using namespace std;

int main()

{

    int fil, col;

    cout << "\nFilas: "; cin >> fil;

    cout << "Columnas: "; cin >> col;

    int matriz[fil][col];

    int matriz2[fil * 3][col * 3];

    int k = 1;

    for (size_t i = 0; i < fil; i++)

        for (size_t j = 0; j < col; j++)

            matriz[i][j] = k++;

    int fil2 = 0, col2 = 0;

    for (size_t i = 0; i < fil; i++)

    {

        col2 = 0;

        for (size_t j = 0; j < col; j++)

        {

            for (size_t a = fil2; a < fil2 + 3; a++)

            {

                for (size_t b = col2; b < col2 + 3; b++)

                {

                    matriz2[a][b] = matriz[i][j];

                }

            }

            col2 += 3;

        }

        fil2 += 3;

    }

    cout << endl;

    for (size_t i = 0; i < fil * 3; i++)

    {

        for (size_t j = 0; j < col * 3; j++)

        {

           cout << matriz2[i][j] << " ";

        }

        cout << endl;

    }

    return 0;

}

for (size_t i = 0; i < fil * 3; i++) {

    for (size_t j = 0; j < col * 3; j++) {

         matriz2[i][j] = matriz[i/3][j/3];

    }

}