From: "Eric I." <rubytraining@...>
Date: 2007-04-16T06:00:05+09:00
Subject: Re: Magic Fingers (#120) [solution]

OK, I made two changes to my code.  First, I don't allow a clap that
ends up with the same finger counts.  Second, I made it possible to
clap all the fingers off of one hand to the other, leaving one hand
with zero.  And now it is the case where the first player is
guaranteed a loss.

Here's my new move table:

       01   02   03   04   11   12   13   14   22   23   24   33
34   44
     ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
----
01:  -1T1 -1T2 -1T3 +1T4 -1T1 -1T2 -1T1 +1T4 -1T2 -1T2 -1T4 -1T3 -1T4
-1T4
02:  +C11 -C11 +2T3 +2T4 +C11 -C11 +2T3 +2T4 -C11 +2T3 +2T4 -C11 -C11 -
C11
03:  +C21 +3T2 +3T3 +3T4 -C21 +3T2 +3T3 +3T4 -C21 -C21 -C21 -C21 -C21 -
C21
04:  +4T1 +4T2 +4T3 +4T4 +C31 +C22  C22 +C22  C22 +C22  C22 -C22 -C22 -
C22
11:  +C02 +1T2 -1T3 +1T4 -1T1 +C02 -1T3 +1T4  C02 -1T2 -1T4 -1T3 +1T4
-1T4
12:  +C03 -2T2 +2T3 +2T4 +C03 +2T2 +2T3 +2T4 -1T2 +2T3 +2T4 -1T3 -2T3
-1T4
13:  +C22 +3T2 +3T3 +3T4 +3T1 +C22 +3T3 +1T4  C22 +C22  C22 -C22  3T3
1T4
14:  +4T1 +4T2 +4T3 +4T4 +C32 -C32 -C32 +C32 -C32 -4T3 -4T2 -1T3 -4T3
-1T4
22:  +C13  2T2 +2T3 +2T4 +C13 +2T2 +2T3 +2T4  2T2 +2T3 +2T4 +2T3 +2T4
2T4
23:  +2T1 +3T2 +3T3 +3T4 +3T1 +3T2 +3T3 +3T4 -3T2 +3T2 -3T2 +3T3 +3T4
-2T4
24:  +4T1 +4T2 +2T3 +2T4 +4T1 +4T2 +2T3 +2T4  2T2 +4T2  4T2 +4T3 +4T4
2T4
33:  +C24 +3T2 +3T3 +3T4 +3T1 +3T2 +3T3 +3T4 +3T2 +3T2 +3T4 +3T3 +3T4
+3T4
34:  +4T1 +4T2 +4T3 +4T4 +4T1 +4T2 +4T3 +4T4 +4T2 +4T3 +4T4 +4T3 +4T4
+4T4
44:  +4T1 +4T2 +4T3 +4T4 +4T1 +4T2 +4T3 +4T4 +4T2 +4T3 +4T4 +4T3 +4T4
+4T4

Interestingly if you follow through starting at 11/11, then the first
player can apparently hold off on losing for 26 turns, 13 by each
player.

And my replacement generate_claps method is appended below.

Eric
----
Are you interested in on-site Ruby training that's been highly
reviewed by former students?  http://LearnRuby.com

====

# Generates an array of Procs, each able to perform a clapping
move.
# See the comment for generate_touches for the remaining details
since
# this method works
analogously.
def generate_claps
  result = []
  (0..1).each do |from_hand|
    to_hand = 1 - from_hand
    (1..4).each do |fingers|
      result << Proc.new do |player_hands, opponent_hands|
        raise "do not have enough fingers on #{HandNames[from_hand]}"
unless
          player_hands[from_hand] >= fingers
        raise "#{HandNames[to_hand]} would end up with five or more
fingers" if
          !AllowClapsToZero && player_hands[to_hand] + fingers >= 5
        raise "cannot end up with same number combination after clap"
if
          player_hands[from_hand] - fingers == player_hands[to_hand]
        description1 = "claps to transfer #{fingers} fingers from " +
          "#{HandNames[from_hand]} to #{HandNames[to_hand]}"
        player_hands[from_hand] -= fingers
        player_hands[to_hand] += fingers
        player_hands[to_hand] = 0 if player_hands[to_hand] >= 5
        description2 =
"C#{player_hands[from_hand]}#{player_hands[to_hand]}"
        [[player_hands, opponent_hands], description1, description2]
      end
    end
  end
  result
end