Конструкторы с параметром, копии и перегрузка операций

#include "stdafx.h"
#include "conio.h"
int n1, n2;
class LIST {
private:
int info; 
LIST *next; 
LIST *prev;
public:
LIST ()
{ 
this->info=0;
this->next=this; 
this->prev=this;
}
int Empty()
{
if (this->next==this && this->prev==this) 
return 1; 
else 
return 0;
}
 
LIST *SearchOnward(int num)
{
LIST *tmp=this->next; 
while(tmp!=this && tmp->info!=num) 
{ 
tmp=tmp->next; 
n1+=1; 
} 
if (tmp!=this) 
return tmp; 
else 
return NULL;
}
 
LIST *SearchBack(int num)
{
LIST *tmp=this->prev; 
while(tmp!=this && tmp->info!=num) 
{ 
tmp=tmp->prev; 
n2+=1; 
} 
if (tmp!=this) 
return tmp; 
else 
return NULL;
}
 
int Del(int num)
{
LIST *current=SearchOnward(num); 
if (current!=NULL) 
{ 
current->prev->next=current->next; 
current->next->prev=current->prev; 
delete current; 
return 1; 
} 
return 0;
}
 
int AddAfter(int num, int point)
{
if (Empty()==1) 
{ 
LIST *tmp= new LIST; 
tmp->next=this; 
tmp->prev=this; 
tmp->info=num; 
this->next=tmp; 
this->prev=tmp; 
return 1; 
} 
LIST *current=SearchOnward(point); 
if (current!=NULL) 
{ 
LIST *tmp= new LIST; 
tmp->next=current->next; 
tmp->prev=current; 
tmp->info=num; 
current->next->prev=tmp; 
current->next=tmp; 
return 1; 
} 
return 0;
}
 
int AddBefore(int num, int point)
{
LIST *current=SearchBack(point); 
if(current!=NULL) 
{ 
LIST *tmp= new LIST; 
tmp->info=num; 
tmp->next=current; 
tmp->prev=current->prev; 
current->prev->next=tmp; 
current->prev=tmp; 
return 1; 
} 
return 0;
}
 
void ShowOnward()
{
LIST *tmp=this->next; 
printf ("In direct way:"); 
while(tmp!=this) 
{ 
printf (" %d ",tmp->info); 
tmp=tmp->next; 
} 
printf ("\n");
}
 
void ShowBack()
{
LIST *tmp=this->prev; 
printf ("In opposite way:"); 
while(tmp!=this) 
{ 
printf (" %d ",tmp->info); 
tmp=tmp->prev; 
} 
printf ("\n");
}
 
};
int main()
{
LIST *HEAD;
HEAD = new LIST;
int num, tmp; 
char otv, otv2; 
do 
{ 
printf ("1. Add element\n2. Delete element\n3. Print\n4. Search\n");
scanf_s ("%d",&otv); 
switch(otv) 
{ 
case 1: 
printf ("Enter element = "); 
scanf_s ("%d",&num); 
if (HEAD->Empty()==1) 
{ 
HEAD->AddAfter(num,0); 
printf ("Element was added\n"); 
} 
else 
{ 
printf ("1. Add before\n2. Add after\n");
scanf_s ("%d",&otv2); 
switch(otv2) 
{ 
case 1: 
printf ("Add before which element = "); 
scanf_s ("%d",&tmp); 
if (HEAD->AddBefore(num,tmp)==1) 
printf ("Element was added\n");
else 
printf ("There's no such element\n"); 
break;
case 2:
printf ("Add after which element = "); 
scanf_s ("%d",&tmp);
if (HEAD->AddAfter(num,tmp)==1) 
printf ("Element was added\n");
else 
printf ("There's no such element\n"); 
break;
default:
printf ("Error!\n"); 
break;
}
}
break;
 
case 2:
if(HEAD->Empty()==1) 
printf ("List is empty\n"); 
else 
{ 
printf ("Deleting element = "); 
scanf_s("%d",&num);
if(HEAD->Del(num)==1) 
printf ("Element was deleted\n"); 
else 
printf ("There's no such element\n"); 
} 
break;
case 3:
if(HEAD->Empty()==1) 
printf ("List is empty\n"); 
else 
{
printf ("1. Go in direct way\n2. Go in opposite way\n");
scanf_s ("%d",&otv2);
switch(otv2)
{
case 1:
HEAD->ShowOnward();
break;
case 2:
HEAD->ShowBack();
break;
default:
printf ("Error!\n"); 
break;
}
 
}
break;
 
case 4:
if(HEAD->Empty()==1) 
printf ("List is empty\n"); 
else 
{ 
printf ("Search for element = "); 
scanf_s ("%d",&num); 
n1=0; 
n2=0; 
if(HEAD->SearchOnward(num)!=NULL && HEAD->SearchBack(num)!=NULL) 
{ 
printf ("Element was found\n"); 
printf ("In direct way step = %d\n",n1); 
printf ("In opposite way step = %d\n",n2); 
} 
else 
printf ("There's no such element\n");
}
break;
 
case 0:
break;
default:
printf ("Error!\n"); 
break;
}
 
}
while (otv!=0);
}