Reversing a Doubly Linked List by Iteration

//Just swap the prev node value with the next node value, with the help of two pointers.

//in case there is no tail pointer, we can have temp pointer always just behind current pointer.

//after coming out of while loop, current and nextnode both will be having null value and temp-

//- will be just behind current, hence the temp will be at last node after the end of loop, hence head=temp.

DoublyLinkedListNode* reverse(DoublyLinkedListNode* head)

{

    DoublyLinkedListNode*current, *nextnode, *temp;

    current=head;

    while(current!=0)

    {

        nextnode=current->next;

        current->next=current->prev;

        current->prev=nextnode;

        temp=current;

        current=nextnode;

    }

    head=temp;

    return head;

}