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.
Received on Mon Jun 26 2006 - 12:58:26 CDT
