Re: Depth First Search of a Char_Matrix?

[Shark8 <onewingedshark@gmail.com>]

On Saturday, April 27, 2013 12:48:09 PM UTC-6, Dmitry A. Kazakov wrote:
> On Sat, 27 Apr 2013 11:16:34 -0700 (PDT), Shark8 wrote:
> 
> > On Saturday, April 27, 2013 11:25:57 AM UTC-6, Jeffrey Carter wrote:
> >> 
> >> There is absolutely no reason to use access types (especially not anonymous 
> >> access types) or addresses for this problem.
> > 
> > Sure, but there's no real reason not to: the illustration was simply a DFS
> > on something that might-not-exist and so null/some-object map to that
> > perfectly fine.
> 
> 
> No, you don't place a key into the map if there is no value for it.

And I don't -- as the algorithm shows, the only place that a new address is placed into the list is when it's been visited for the first time, this is after the cases of a null board-space and an already-visited node have been checked (which return out of the function).

{i.e. it's a list of already-visited nodes, so that the recursion is not infinite.}

> > It's an error to ask "what color is the piece at X,Y?" when the element
> > X,Y contains no piece;
> 
> Likely