Gentlemen,
I'm quite confused about the proper implementation for the following
classes. I've provide an implementation as I understand it, however my
understand is paltry at best. The intent is to create a linked list
implementation of the list ADT. Please guide me in the right direction.

template < class T >
class node
{
  private:
    node ( const T& something, node* nextPtr );
    T info;
    node* next;

  friend class list<T>;
};

template < class T >
class list
{
  public:
    list ( int i = 0 );
    ~list ();

  private:
    ListNode<T>* beginning;  // Pointer to beginning of list
    ListNode<T>* location;   // Location pointer
};

// implementation
template < class T >
node<T>::node ( const T& something, node* nextPtr )
{
  info = something;
  next = nextPtr;
}

template < class T >
list<T>::list(int i);
{
  beginning = new node<T>;
  location = NULL;
}

As always,
Thanks in advance,
Andrew

Who not used STL?



Andrew Edwards wrote:

> Gentlemen,
> I'm quite confused about the proper implementation for the following
> classes. I've provide an implementation as I understand it, however my
> understand is paltry at best. The intent is to create a linked list
> implementation of the list ADT. Please guide me in the right direction.
>
> template < class T >
> class node
> {
>   private:
>     node ( const T& something, node* nextPtr );
>     T info;
>     node* next;
>
>   friend class list<T>;
> };
>
> template < class T >
> class list
> {
>   public:
>     list ( int i = 0 );
>     ~list ();
>
>   private:
>     ListNode<T>* beginning;  // Pointer to beginning of list
>     ListNode<T>* location;   // Location pointer
> };
>
> // implementation
> template < class T >
> node<T>::node ( const T& something, node* nextPtr )
> {
>   info = something;
>   next = nextPtr;
> }
>
> template < class T >
> list<T>::list(int i);
> {
>   beginning = new node<T>;
>   location = NULL;
> }
>
> As always,
> Thanks in advance,
> Andrew

--
ManiaC++
Jan Knepper

"Jan Knepper" <jan@smartsoft.us> wrote...
> Who not used STL?

I'm assuming you are asking why I do not use STL. In short, I'm taking a C++ Data Structures class which requires that I implement my own.

If I've made the wrong assumption about your question, please clarify!

Andrew

As yet you've only implemented a partial linked list implementation. You're still lacking functions which would allow you to insert, add, remove, get, find node's to/in/from the list. These functions are the most essential functions as these will enforce the actual data structure. Also in the list constructor you create a new node for beginning, I'm assuming you want that to be a dummy node indicating the beginning of the list, in that case you'll want to make it clear for yourself that that is a dummy node by setting it's info to 0. You'll have a problem there though as info is a reference, which can't be uninitialized, thus you can't really make a dummy node. So, you have two options, one is to use a pointer instead of a reference in the node, which you could set to 0 just as with the next pointer. Or you need to forget about a dummy node and just do your accounting in the management functions. But that will require some extra code in your list management functions, most specifically, when adding nodes to you list, you first need to check if it's empty (ie beginning is set to 0) in which case you need to set beginning, in all other case you need to set one of the next pointers of one of the nodes in the list.

All in all you still have quite a bit to do, I'd recommend you read over your text books again and all the important parts, making a linked list implementation isn't really difficult, you just need to get the right idea of it first.

Regards,

Remko van der Vossen

"Andrew Edwards" <edwardsac@spamfreeusa.com> wrote in message news:be7aq9$2g2r$1@digitaldaemon.com...
> Gentlemen,
> I'm quite confused about the proper implementation for the following
> classes. I've provide an implementation as I understand it, however my
> understand is paltry at best. The intent is to create a linked list
> implementation of the list ADT. Please guide me in the right direction.
>
> template < class T >
> class node
> {
>   private:
>     node ( const T& something, node* nextPtr );
>     T info;
>     node* next;
>
>   friend class list<T>;
> };
>
> template < class T >
> class list
> {
>   public:
>     list ( int i = 0 );
>     ~list ();
>
>   private:
>     ListNode<T>* beginning;  // Pointer to beginning of list
>     ListNode<T>* location;   // Location pointer
> };
>
> // implementation
> template < class T >
> node<T>::node ( const T& something, node* nextPtr )
> {
>   info = something;
>   next = nextPtr;
> }
>
> template < class T >
> list<T>::list(int i);
> {
>   beginning = new node<T>;
>   location = NULL;
> }
>
> As always,
> Thanks in advance,
> Andrew
>
>

Thanks for taking the time to reply to this post.

I am aware of all the parts necessary to fully implement a linked list: However, I did not provide enough information or explain myself clearly enough.

Since I am doing my homework I did not want to put too much of my code forward. I problem was understanding how to implement the constructor of the two classes. Additionally, I wasn't able to visualize how to access members of one class through the other.

You are quite right though! Implementing a linked list isn't really difficult. Once I understood how to implement the constructors and how to access the members of each class through one object that is!

As always, your assistance was greatly appreciated!

Regards,
Andrew

Andrew Edwards wrote:

> "Jan Knepper" <jan@smartsoft.us> wrote...
> > Who not used STL?
>
> I'm assuming you are asking why I do not use STL. In short, I'm taking a C++ Data Structures class which requires that I implement my own.
>
> If I've made the wrong assumption about your question, please clarify!

No, that was the question...
I often wonder why people implement existing code, it's kinda like re-inventing
the wheel. Of course in your case the reason is obvious.


--
ManiaC++
Jan Knepper