/*****************************************
 ** This program demonstrates an iterative
 ** approach to producing a reverse copy of 
 ** a list, i.e. a new list whose nodes have 
 ** all the same values in the reverse order.
 ** Doing this recursively is more difficult!
 *****************************************/
#include <iostream>
using namespace std;

/*****************************************
 ** struct def's and function prototypes
 *****************************************/
struct Node
{
  double data;
  Node *next;
};

Node* add2front(double val, Node* L);
void printlist(Node* L);
Node* reverse(Node* L);

/*****************************************
 ** MAIN
 *****************************************/
int main()
{
  // Get original list of values from user
  Node* L = NULL;
  double x;
  while(cin >> x)
    L = add2front(x,L);

  // Make copy in reverse
  Node *Lp = reverse(L);
  
  // Print both to show they're reverses!
  printlist(L);
  cout << endl;
  printlist(Lp);
  cout << endl;

  return 0;
}

/*****************************************
 ** Function definitions
 *****************************************/
Node* reverse(Node* L)
{
  Node* R = NULL;
  for(Node *p = L; p != 0; p = p->next)
    R = add2front(p->data,R);
  return R;
}

Node* add2front(double val, Node* L)
{
  Node* T = new Node{val, L};
  return T;
}

void printlist(Node* L)
{
  for(Node* T = L; T != NULL; T = T->next)
      cout << T->data << ' ';
}