#ifndef _DOUBLY_LINKED_LISTS_OF_SINGLY_LINKED_NODES_H
#define _DOUBLY_LINKED_LISTS_OF_SINGLY_LINKED_NODES_H

#include <SinglyLinkedListsOfSinglyLinkedNodes.h>

class DoublyLinkedListsOfSinglyLinkedNodes : public SinglyLinkedListsOfSinglyLinkedNodes {
    public:
                      DoublyLinkedListsOfSinglyLinkedNodes();

        virtual List *copy();

        virtual void  append(List *, List *);
        virtual void  insert(List *, List *);
        virtual List *obtain(List *);

                List *getPrev();
                void  setPrev(List *);

        virtual      ~DoublyLinkedListsOfSinglyLinkedNodes();

    protected:
        virtual List *setListNumber(int)    { return(NULL); };
        virtual int   getListNumber(List *) { return(-1);   };
    
    private:
                List *prev;
};
#endif