Linked List Classes

#include <stdio.h>
#include <iostream.h>

struct item
{
    long data;
    item *next;
    item *previous;
    
    item(void)
    {
        data = 0;
        next = previous = NULL;
    }
};

/* Single Linked List 
 *
 * Structure: head -> next -> next .... -> tail (null)
*/

struct SLLIST
{
    item *head;
    item *tail;
    item *current;
    unsigned int listcount;
    
    SLLIST(void)
    {
        head = new item;
        tail = current = head;
        listcount = 1;
    }
    ~SLLIST(void)
    {
        item *temp = head;
        current = head;
        while (current != NULL)
        {
            current = current->next;
            delete temp;
            temp = current;
        }
    }
    int operator[](int index) /* index list like a normal array */
    {
        if(index >= listcount)
            index %= listcount; // wrap array
        item *temp = head;
        for(int i = 0; i < index; i++)
            temp = temp->next;
        current = temp;
        return temp->data;
    }
    void addnode(int data)
    {
        tail->next = new item;
        tail = tail->next;
        tail->data = data;
        listcount++;
    }
    void PrintToConsole(void)
    {
         item *temp = head;
         current = head;
         while (current != NULL)
         {
             current = current->next;
             cout << temp->data << "\n";
             temp = current;
         }
    }
};

/* Doubly linked list
 *
 * Structure: Head <-> next <-> next .... <-> tail (null)
*/

struct DLLIST
{
    item *head;
    item *tail;
    item *current;
    unsigned int listcount;
    
    DLLIST(void)
    {
        head = new item;
        tail = current = head;
        listcount = 1;
    }
    ~DLLIST(void)
    {
        item *temp = head;
        current = head;
        while (current != NULL)
        {
            current = current->next;
            delete temp;
            temp = current;
        }
    }
    int operator[](int index) /* index list like a normal array */
    {
        if(index >= listcount)
            index %= listcount; // wrap array
        item *temp = head;
        for(int i = 0; i < index; i++)
            temp = temp->next;
        current = temp;
        return temp->data;
    }
    void advance(void)
    {
        if(current->next != NULL)
            current = current->next;
    }
    void rewind(void)
    {
        if(current->previous != NULL)
            current = current->previous;
    }
    void addnode(int data)
    {
        tail->next = new item;
        tail->next->previous = tail; // link new back to old tail
        tail = tail->next;
        tail->data = data;
        listcount++;
    }
    void PrintToConsole(void)
    {
         item *temp = head;
         current = head;
         while (current != NULL)
         {
             current = current->next;
             cout << temp->data << "\n";
             temp = current;
         }
    }
};