------_ extPart_001_01C61018.17A77DB0 Content-Type: text/plain; charset s-ascii" Content-Transfer-Encoding: quoted-printable I used dijkstra again for this quiz, which is fine for the short paths, but you really need to be pulling out that bitwise magic for those long paths. http://members.iinet.net.au/~soxbox/ruby_quiz_60/quiz_60.rb http://members.iinet.net.au/~soxbox/ruby_quiz_60/dijkstra.rb That dijkstra.rb is a big improvement over the one I last used in a quiz (don't remember which one that was). My old library only worked if the each_neighbours function was symmetrical, and had a bunch of other inefficiencies. I also included a new SimpleDijkstra module for situations where distances between nodes are uniform (ie. most of these types of puzzles). I also made an implementation using Brian Schroeder's PriorityQueue library (http://ruby.brian-schroeder.de/priority-queue/), but for some reason that ended up being even slower. I haven't looked into whether that was my fault yet, but I'm assuming it is: http://members.iinet.net.au/~soxbox/ruby_quiz_60/quiz_60_priority_queue. rb ##################################################################################### This e-mail message has been scanned for Viruses and Content and cleared y NetIQ MailMarshal ##################################################################################### ------_ extPart_001_01C61018.17A77DB0--