Any Java Gurus?

Sorry about a java question on a c++ board, but this is the best place I've found to get some answers.

I'm sure the answer won't be much diifferent anyway. lol

I am trying to create a 2 dimensional LinkedList . How do I do this??!!!!!!

Part of my code:

// list is a linked list. I am trying to add
// the required amount of queues to it

for (int w = 0; w < num; w++)
{
list.add(new LinkedList());
}

// next, I want to add the elements to
// the first queue and print out the
// results each time.

process = new Process (arrive, service, pid);
list.get(0).add(process);
finalChange = (Process)list.get(0).get(0);
System.out.println (finalChange.pid);

I would have thought that list.get(0) would get me the reference that I needed to access the LinkedList that carries queue #1. The compiler does not seem to like this reference.

Any ideas?

atleats put it under general. only c++prgoraming come to this forum. u would have to get lucky to ifn someone who knows both, if you wont a reply post on general

You'll probably get flamed for posting a Java question, and redirected to a Java board somewhere else.

You need to remember your casts though. get(0) (as an aside, perhaps you should use getFirst() instead of get(0), it's probably faster) returns an Object, not a LinkedList.

Code:

---

process = new Process (arrive, service, pid);
// list.get(0).add(process); // Object has no add method
((LinkedList) list.getFirst()).add(process)
// finalChange = (Process)list.get(0).get(0); // same problem
finalChange = (Process) ((LinkedList) list.getFirst()).getFirst()
System.out.println (finalChange.pid);

---

You could probably sneak a java question onto the C# board...although I'm pretty experienced in java and have never been on the C# board.

>> I'm pretty experienced in java and have never been on the C# board.

And did you know that MY best quality is that i'm just so modest :D ...

Here is a great java forum

http://forum.java.sun.com/

Thanks for reponding SilentStrike! I thought for sure your idea would have worked cause it made sense. But, alas, it does not. I will try to post in general. Don't want to make C++ gurus mad.:)

What errors does the compiler say?

>I am trying to create a 2 dimensional LinkedList . How do I do this??!!!!!!
Forget about the language and go back to the data structure. Imagine a 2 x 2 linked matrix, this can be done very easily in any language that supports a linked data structure. There is one big consideration though, if you only want to traverse the list as you would a two dimensional array, like so:

Code:

---

a[0][0]
a[0][1]
a[1][0]
a[1][1]

---

Then you probably would be better off with just a simple linked list since the principle is the same, you go through the list in a linear motion. If, however, your goal is to go from say a[0][0] to a[1][0] without having to go through all of the first row then a linked matrix would be appropriate. To make such a matrix, consider the declaration:

Code:

---

// Big time pseudocode, I never use Java :P */
public class LinkedMatrix
{
  // Data here
  LinkedMatrix up;
  LinkedMatrix down;
  LinkedMatrix left;
  LinkedMatrix right;
}

---

Instead of just a next link, you have four, one for each direction in the matrix. Building the matrix is of course, more difficult. :) You have to consider normal traversal from a[0][1] to a[1][0] as well as any non-linear traversal.

-Prelude