From: Christian Neukirchen <chneukirchen@...>
Date: 2005-01-28T00:29:12+09:00
Subject: Re: [SUMMARY] Paper Rock Scissors (#16)

Ruby Quiz <james@grayproductions.net> writes:

> I really should show all of those here, but that would make for a ridiculously
> large summary.  Let's go with Christian's favorite:
>
> 	class CNBiasInverter < Player
> 	  def initialize(opponent)
> 		super
> 		@biases = {:rock => 0, :scissors => 0, :paper => 0}
> 		@hit = {:rock => :paper, :paper => :scissors, :scissors => :rock}
> 	  end
> 	  
> 	  def choose
> 		n = ::Kernel.rand(@biases[:rock] + @biases[:scissors] +
> 		    @biases[:paper]).to_i
> 		case n
> 		when 0..@biases[:rock]
> 		  :paper
> 		when @biases[:rock]..@biases[:rock]+@biases[:scissors]
> 		  :rock
> 		when @biases[:rock]+@biases[:scissors]..@biases[:rock]+
> 		     @biases[:scissors]+@biases[:paper]
> 		  :scissors
> 		else
> 		  p @biases[:rock]+@biases[:scissors]..@biases[:paper]
> 		  abort n.to_s
> 		end
> 	  end
> 	  
> 	  def result( you, them, win_lose_or_draw )
> 		@biases[them] += 1
> 	  end
> 	end
>
> initialize() sets up the a Hash for tracking the biases.  (I don't believe @hit
> is needed.)  result() is the compliment to that.  It adjusts the proper bias
> count each time the opponent makes a selection.

Yeah, that @hit was a left-over of a half-way done refactoring. :-)

> choose() does all the interesting work.  A random number is chosen between 0 and
> the total of all the bias counts.  That number is then associated with the
> indicated bias by some clever use of ranges and the opposite of that bias is
> returned as CNBiasInverter's choice.

BTW, I'd be interested if anyone found a nicer looking solution to
do a weighted rand.

> There were many, many interesting strategies, like the one above.  But random
> remained the great equalizer.  Which leads us to the critical question:  What
> exactly is the point of this exercise?
>
> Cheating, of course!

ROFL.

> There were other great cheats.  Jannis Harder's self-repairing program and
> FGSpyPlayer (well commented) are both worth studying.  Some cheating approaches
> were also overlooked.  For example, no one tried to modify the score, but it can
> be done.  There were also a lot of excellent non-cheating solutions.  Which
> leaves me with no choice but to say the lame but utterly true, "All the
> submissions are worth a look!"
>
> My thanks to all my fellow cheaters and the rule abiding players that tolerate
> our antics.

Someone proposed printing the result by oneselves and then
exiting. :-)

-- 
Christian Neukirchen  <chneukirchen@gmail.com>  http://chneukirchen.org