//Demonstration of a linked list Element after Scansholm Chapter 13.1  Pages 470-475
#include <iostream>
#include <stdexcept>
using namespace std;

class Element{
 public:
   Element *next;
   int data;
   Element( Element *n, int d): next(n), data(d){}
   void debug(){ cerr << (unsigned int)this << ":Element[next="<<(unsigned int)next<<", data="
		<< data << "]\n"; }
};

void print(Element *first)
{
   if(first)
   {
	for(Element * p = first; p!=NULL; p=p->next)
		p->debug();
   }else{
	cerr << "NULL\n";
   }
	cerr << "---------------\n";
}
void wait()
{
	cout << "?"; cin.get();
}
int main()
{
	Element * first =0;
	print(first);

	wait();

	first = new Element(first, 5);
	print(first);

	wait();

	first = new Element(first, 3);
	print(first);

	wait();

	first = new Element(first, 4);
	print(first);

	wait();

	first = new Element(first, 42);
	print(first);
}