class matrix
{ protected:

// 1d

    int size;                        // C++   void f(int x[])
    int * data;

    int position(int i) const
    { return i; }

// 2d

    int rows, cols;                // C++   void f(int x[][10])
    int * data;

    int position(int i, int j) const
    { return i*cols + j; }


// 3d

    int rows, cols, planes;       // C++    void f(int x[][10][7])
    int * data;

    int position(int i, int j, int k) const
    { return i*rows*cols + j*cols + k; }

// etc

  public:

    matrix(int r, int c, int p)
    { cout << "  regular constructor\n";
      rows = r;
      cols = c;
      planes = p;
      data = new int [r*c*p]; }

    ~matrix()
    { cout << "  destructor happening\n";
      delete [] data; }

    int numrows() const
    { return rows; }

    int numcols() const
    { return cols; }

    int numplanes() const
    { return planes; }

    bool safe_access(int i, int j, int k) const
    { if (i<0 || j<0 || i>=rows || j>=cols || k<0 || k>=planes)
        return false;
      return true; }

    int get(int i, int j, int k) const
    { if (! safe_access(i, j, k))
      { cerr << "\narray access out of bounds\n";
        exit(1); }
      return data[position(i, j, k)]; }

    void put(int i, int j, int k, int value)
    { if (! safe_access(i, j, k))
      { cerr << "\narray access out of bounds\n";
        exit(1); }
      data[position(i, j, k)] = value; }

// etc etc etc