///////    File Vector.h    ///////
#ifndef  Vector_SEEN__
#define  Vector_SEEN__
#include <stdlib.h>

typedef unsigned int Dim;
#define OP operator

class Vector
{     friend Vector& OP += (Vector&, const Vector&);
      friend Vector OP * (const Vector& v, double s);
   public:
      Vector();
      Vector(Dim n);
      Vector(Dim n, double* arr);
      ~Vector() {  delete v; }            // destructor
      Vector(const Vector& vec);          // copy constructor
      Vector&  OP =  (const Vector& vec); // assignment
      Vector&  OP += (const Vector& vec);
      double&  OP [] (int i);
      Vector   OP + (const Vector& vec) const;
      Vector&  OP * (const Vector& vec) const;
      void display();
   protected:
      double*   v;   // dynamic double array
      Dim     len;   // vector length
      double inner(double* w);
};

inline Vector OP * (double s, const Vector& v)
       {   return( v * s );
       }

inline Vector::Vector()       // default constructor
       : v(NULL), len(0)      
       { }

inline Vector::Vector(Dim n)  // constructor
       : v(new double[n]), len(n)
       { }

#endif
///////    End of File Vector.h    ///////