Vector. Scalar Product

class Vector // C++
{
public:
  int dx, dy;
  Vector(void); // Constructor. Read the vector coordinates
  double Len(void); // Return the length of a vector
  int operator *(Vector &b); // Overload operator *: return the scalar product
  double GetAngle(Vector &b); // Return in radians the angle between current vector and vector b
};

class Vector // Java
{
  private int dx, dy;
  Vector(); // Constructor, creates vector (0, 0)
  Vector(int dx, int dy); // Constructor, creates vector (dx, dy)
  public double getLength(void); // Returns the length of the vector
  public int Scalar(Vector v); // Returns the scalar product of current vector and vector v
  public double GetAngle(Vector v); // Returns in radians the angle between current vector and vector v
};