From: James Edward Gray II <james@...>
Date: 2007-03-07T00:30:28+09:00
Subject: Re: [QUIZ] GOPS (#116)

On Mar 4, 2007, at 3:55 PM, Christoffer Lern� wrote:

> Here is an example of what can be done with a static strategy.

Here's my favorite strategy I've been able to come up with.

The idea is to toss little cards until we notice sure wins.  For  
example, after the opponent has played his King, ours is a sure win.   
At that point we find the highest bid card remaining and set the King  
aside for winning that.  Then we start watching for the Queen...

It's pretty dependent on the bid card order, so muppet still does  
pretty well against it and even random gets the better of it from  
time to time.

Here's the code:

#!/usr/bin/env ruby -w

class Player
   CARDS = (1..13).to_a

   def initialize
     @cards_left = CARDS.dup
     @wins       = Array.new
   end

   attr_reader :cards_left
   protected   :cards_left

   def play_card(card)
     @cards_left.delete(card)
   end

   def win_card(bid_card)
     @wins << bid_card
   end
end


class Planner < Player
   def initialize
     super

     @bids_left = CARDS.dup
     @opponent  = Player.new

     @sure_wins = Hash.new
   end

   def bid_on_card(card)
     @bidding_for = card
     @last_play   = choose_a_card
   end

   def record_result(opponents_card)
     if @last_play > opponents_card
       win_card(@bidding_for)
     elsif opponents_card > @last_play
       @opponent.win_card(@bidding_for)
     end

     @bids_left.delete(@bidding_for)
     play_card(@last_play)
     @opponent.play_card(opponents_card)
   end

   private

   def choose_a_card
     find_sure_wins

     @sure_wins[@bidding_for] || @cards_left.min
   end

   def find_sure_wins
     ((@opponent.cards_left.last + 1)..13).to_a.reverse_each do |card|
       next unless @cards_left.include?       card
       next if     @sure_wins.values.include? card
       next unless targets = @bids_left - @sure_wins.keys

       @sure_wins[targets.max] = card
     end
   end
end

if __FILE__ == $PROGRAM_NAME
   planner = Planner.new
   13.times do
     $stdout.puts planner.bid_on_card($stdin.gets[/\d+/].to_i)
     $stdout.flush
     planner.record_result($stdin.gets[/\d+/].to_i)
   end
end

__END__

James Edward Gray II