From: Daniel Martin <martin@...>
Date: 2006-08-16T11:21:14+09:00
Subject: Re: [QUIZ] Newbie doubts about the quiz

"Marcelo Alvim" <malvim@gmail.com> writes:

> 4) You guys could teach me a super-cool Ruby-esque way to do that that
> I can't even think about right now.

Note that what I did to solve this was at each step to copy the cells
in the neighborhood of the current cell to a 13 by 13 array so that
the current cell is the middle.  This then frees me from thinking
about wraparound or bounds checking while computing which move to make
next.

Of course, this is only possible if you have a fast way to copy a
rectangular chunk of one two-dimensional array to another.  Since I
was using NArray, I had that.

http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/208295