class Matrix {
private:
    size_t w, h;
    double *data;
public:
    constexpr Matrix() : data{ nullptr }, w{ 0 }, h{ 0 } {};
    Matrix(size_t width, size_t height) :w{width}, h{height}
    {
        data = new double[w * h];
        for (size_t i = 0; i < w * h; i++) {
            data[i] = 0;
        }
    }

    Matrix(const Matrix& other) : w{other.w}, h{other.w}
    {
        data = new double[w * h];
        for (size_t i = 0; i < w * h; i++) {
            data[i] = other.data[i];
        }
    }

    ~Matrix()
    {
        delete[] data;
    }

    size_t width() const { return w; }
    size_t height() const { return h; }

    double& operator()(size_t i, size_t j)
    {
        int idx = w*(j - 1) + (i - 1);
        if (idx < 0 || idx > w*h)
            throw std::out_of_range("");
        return data[idx];
    }

    const double& operator()(size_t i, size_t j) const
    {
        int idx = w*(j - 1) + (i - 1);
        if (idx < 0 || idx > w*h)
            throw std::out_of_range("");
        return data[idx];
    }
};

std::ostream& operator<<(std::ostream& os, const Matrix& matrix)
{
    const size_t w = matrix.width();
    const size_t h = matrix.height();

    os << std::endl << '[';
    for (size_t i = 1; i <= w; i++) {
        if (i != 1)
            os << ' ';
        for (size_t j = 1; j <= h; j++) {
            os << matrix(i, j);
            if (j != h)
                os << "\t";
        }
        if (i == w)
            os << ']';
        os << std::endl;
    }

    return os;
}

int main()
{
    auto m = Matrix(3, 3);
    std::cout << "m: " << m << std::endl;
    m(1, 1) = 1;
    m(3, 3) = 9;
    std::cout << "m: " << m << std::endl;

    auto m1 = Matrix(3, 3);
}