#include <iostream>
using namespace std;

struct Node
{
   int data;
   Node* next;
};

void printList( Node* start )
{
   while ( start != NULL  )
   {
      //print current element
      cout << start -> data <<endl;
      //advance down the list
      start = start -> next;
   }
}

int main()
{
   Node* head = NULL;  //create holder for start of list
   head = new Node();  //allocate space for node, return ptr
   head -> data = 1;   //dereference head, use dot op. and assign 1
   head -> next = NULL;
   printList ( head ); 
   
   Node* temp = new Node(); // create a temp pointer
   temp -> data = 2;
   temp -> next = NULL;
   head -> next = temp;

   temp = NULL;

   printList( head );
}