Re: dual graph

From: Keith H Duggar <duggar_at_alum.mit.edu>
Date: 26 Jun 2006 10:58:26 -0700
Message-ID: <1151344706.642876.20890_at_u72g2000cwu.googlegroups.com>


Chris Smith wrote:
> Marshall <marshall.spight_at_gmail.com> wrote:
> > I would have thought that to call an acyclic graph a
> > tree, it would have to have a distinguished node. Yes?
> > No? My answer to David's question would have been
> > "acyclic." But again: not my field.
>
> In graph theory, no, a tree need not have any specific
> root node. At least, I've never seen anyone in graph
> theory define a tree with a distinguished root node. It's
> not really my field, either... more of a casual interest.

You are correct. A tree does not have any special node. If a root node is specified then it is called a /rooted tree/. In fact many algorithms (various tree balancing schemes) often change the node designated as the root to balance the tree.

  • Keith -- Fraud 6
Received on Mon Jun 26 2006 - 19:58:26 CEST

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