///////     File :  NList.C    ///////
//  nested list objects
#include <iostream.h>
#include "NList.h"

void NList::display(NItem* p, int r /* = 0 */)
{   cout << "(";
    while ( p )
    {    if ( p->l_c )
            cout << p->ch;
         else
            display(p->lis, 1);
         if ( p = p->next ) cout << " ";
    }
    cout << ")";
    if (r == 0 ) cout << "\n";
}

int NList::put_on(char c)
{  NItem* tmp = new NItem(c,head);
      if ( tmp )
      {  head = tmp;
         return(0);
      }
      else return(-1); // failed
}


int NList::put_on(NList& nl)
{  NItem* tmp = new NItem(nl.head, head);
      if ( tmp )
      {  head = tmp;
         return(0);
      }
      else return(-1); // failed
}

int main()
{  NList aa('A'), bb('B'), cd('D');
   cd.put_on('C');
   bb.put_on(cd);
   aa.put_on(bb);
   aa.display();
}