struct Matrix
{
    double** matrix;
    int n;
    int m;
};

struct Matrix getMatrix(int n, int m)
{
    struct Matrix result;

    result.n = n;
    result.m = m;

    result.matrix = (double*)calloc(n, sizeof(double*));

    for (int i = 0; i < n; i++)
    {
        double* arr = (double*)calloc(m, sizeof(double*));
        result.matrix[i] = arr;
    }

    return result;
}

int main()
{
    struct Matrix matrix1 = getMatrix(2, 3);
    struct Matrix matrix2 = getMatrix(3, 4);

    free(&matrix1);
    free(&matrix2);

    getchar();
    return 0;
}