#include <iostream.h>
#include <math.h>

//****** main function *****************

class vecNd {
private:
  int N;
  double * x;
public:
  vecNd(int _N) {
    N = _N;
    x = new double[N];
    for (int i=0;i<N;i++) x[i] = 0.;
  };

  void SetX_i(int i,double newx) {
    if ((i<0) || (i>N-1)) {
      cout<<"Component out of bounds ! Leave component."<<endl;
      return;
    }
    x[i] = newx;
  };

  double GetX_i(int i) {
    if ((i<0) || (i>N-1)) {
      cout<<"Component out of bounds ! Leave component."<<endl;
      return 0.;
    }
    return x[i];
  };

  double Length() {
    double length2 = 0.;
    for (int i=0;i<N;i++) length2 += x[i]*x[i];
    return sqrt(length2);
  };

  vecNd Direction() {
    double length = Length();
    vecNd direction(N);
    for (int i=0;i<N;i++) direction.SetX_i(i,x[i]/length);
    return direction;
  };
};

void main() {  
  for (int i=0;i<10;i++) { 
    cout<<"cos(i="<<i<<") = "<<cos(i)<<" "<<sin(i)<<endl<<endl;
  }
  cout<<" 17/5 = "<<17/5<<" ... "<<17./5.<<endl;

  vecNd * testvec;
  testvec = new vecNd(17);
  for (int i=0;i<17;i++) testvec->SetX_i(i,i*i/3.);
  cout<<" Vector : ";
  for (int i=0;i<16;i++) {
    cout<<testvec->GetX_i(i)<<", ";
  }
  cout<<testvec->GetX_i(16)<<endl;

  cout<<"Length ="<<testvec->Length()<<endl;
  cout<<" Direction : ";
  for (int i=0;i<16;i++) {
    cout<<(testvec->Direction()).GetX_i(i)<<", ";
  }
  cout<<(testvec->Direction()).GetX_i(16)<<endl;

  vecNd testvec1(17);
  for (int i=0;i<17;i++) testvec1.SetX_i(i,i*i*i/5.);
  cout<<" Vector : ";
  for (int i=0;i<16;i++) {
    cout<<testvec1.GetX_i(i)<<", ";
  }
  cout<<testvec1.GetX_i(16)<<endl;

  vecNd ** field;
  field = new vecNd*[2];
  for (int i=0;i<2;i++) {
    field[i] = new vecNd(2);
    for (int j=0;j<2;j++) {
      field[i]->SetX_i(j,double(j*j/(i+1.)));
    }
  }
};