第14回オフラインリアルタイムどう書くの問題をRubyで解く

def battle(ms, ws)
  mh = {:B=>:a,:D=>:c,:F=>:e,:H=>:g,:J=>:i,:L=>:k}
  wh = {:B=>:c,:D=>:e,:F=>:g,:H=>:i,:J=>:k,:L=>:a}
  ms_k, ms_a = ms.partition{|m| ws.include?(mh[m])}
  return 0 if ms_k.size == 0
  ws_a = ms_k.map{|m| wh[m]}
  battle(ms_a, ws_a) + ms_k.size
end

def solve(q)
  ms, ws = q.chars.map(&:to_sym).partition{|e| (:A..:Z).include?(e)}
  battle(ms, ws)
end

DATA.readlines.each do |line|
  no,q,a = line.chop.split(/\s+/)
  ans = solve(q)
  print no + "\t" + ans.to_s
  puts ans == a.to_i ? ' o' : ' x'
end
__END__
0	gLDLBgBgHDaD	6
1	DBcDLaLgDBH	6
2	JJca	0