Список типа "ОЧЕРЕДЬ"

 
#include <iostream>
 
using namespace std;
 
int main(void)
{
    int n = 5;
    int &q1 = n;
    int &q2 = q1;
    int &q3 = q2;
    
    cout << q1
         << q2
         << q3
         << endl;
    
    n = 1;
    
    cout << q1
         << q2
         << q3
         << endl;
        
    return 0;
}

class el_o4{
       el_o4 *next;
       int el;
}
 
class o4{
        el_o4 *beg = NULL;
//ну и методы
}

struct Dec
{
 int el;
 Dec *next;
};
 
struct BE
{
 Dec *beg;
 Dec *end;
};
 
 
void AddR(BE *pbe,int ii)
{
 void in(BE*,int);
 void erin();
 if (initbool)
 {
  if (pbe->beg == NULL)
  {
   in(pbe,ii);
  }
  else
  {
   pbe->end->next = new Dec;
   pbe->end = pbe->end->next;
   pbe->end->el = ii;
   pbe->end->next = NULL;
  }
  del = 1;
  printf("Addition on the right................................. [OK]");
 }
 else erin();
};
 
void AddL(BE *pbe, int ii)
{
 void in(BE*,int);
 void erin();
 if (initbool)
 {
  if (pbe->beg == NULL)
  {
   in(pbe,ii);
  }
  else
  {
   Dec *p = new Dec;
   p->next = pbe->beg;
   pbe->beg = p;
   pbe->beg->el = ii;
  }
  del = 1;
  printf("Addition on the left.................................. [OK]");
 }
 else erin();
};
 
void in(BE *pbe, int ii)
{
 pbe->beg = new Dec;
 pbe->end = pbe->beg;
 pbe->beg->next = NULL;
 pbe->beg->el = ii;
};
 
 
int *DelR(BE *pbe)
{
 void erdel();
 void erin();
 int n;
 Dec *p;
 if (initbool)
  if (del)
  {
   if (pbe->beg == pbe->end)
   {
    p = pbe->beg;
    pbe->beg = NULL;
    pbe->end = NULL;
    del = 0;
   }
   else
   {
    p = pbe->beg;
    while (p->next!=pbe->end)
    {
     p = p->next;
    }
    pbe->end = p;
    pbe->end->next = NULL;
    p = p->next;
   }
   n=p->el;
   delete p;
   printf("Delete on the left.................................... [OK]");
   return &n;
  }
  else {erdel(); return NULL;}
  else {erin(); return NULL;}
};
 
int *DelL(BE *pbe)
{
 void erin();
 void erdel();
 Dec *p;
 int n;
 if (initbool)
 if (del)
 {
  if (pbe->beg == pbe->end)
  {
   p = pbe->beg;
   pbe->beg = NULL;
   pbe->end = NULL;
   del = 0;
  }
  else
  {
   p = pbe->beg;
   pbe->beg = pbe->beg->next;
  }
  n=p->el;
  delete p;
  printf("Delete on the right................................... [OK]");
  return &n;
 }
 else {erdel(); return NULL;}
 else {erin(); return NULL;}
};
 
void DelAll(BE *pbe)
{
 Dec *p;
 
 while(pbe->beg!=pbe->end)
 {
  p = pbe->beg;
  while(p->next!=pbe->end)
  {
   p = p->next;
  }
  pbe->end = p;
  delete p;
 }
 del = 0;
 printf("Delete All............................................ [OK]\n");
};