const    int GON = 32;
const    double Pi = 3.1415926535897;
const    int size = 1000;   // max number of vertices                    
extern   int vnum;
extern   FILE *fp;


struct vector {
   double coord[3];
   double norm (void);
   double& operator [](int i) { return coord[i];}
   void fprint() 
     { fprintf(fp, "%14.8f, %14.8f, %14.8f\n", coord[0],coord[1],coord[2]);}
 };

struct knots {
   vector p[size];
   vector& operator [](int i) { return p[i];}
   knots& operator =(knots& a) {
      for (int i=0; i<vnum; i++) p[i] = a.p[i]; 
      return (*this); }
 };

/*
struct knots {
   vector* p;
   knots(void) { p = new vector[size]; }
   ~knots(void) { delete p;}
   vector& operator [](int i) { return p[i];}
   knots& operator =(knots& a) {
      for (int i=0; i<vnum; i++) p[i] = a.p[i]; 
      return (*this); }
 };
 */

vector operator +(vector a, vector b);
vector operator -(vector a, vector b);
vector operator -(vector a);
vector operator *(double x, vector b);
double operator *(vector a, vector b);
vector operator &(vector a, vector  b);
vector vect(double a, double b, double c);
knots  operator +(knots a, knots b);