第10回オフラインリアルタイムどう書くの問題をRubyで解く

BOARD = <<-EOD
!!!!!!!!!
!!!!!!!!!
!!!!T!!!!
!!!k!U!!!
!!j!H!V!!
!i!S!I!W!
!!R!B!J!!
!h!G!C!X!
!!Q!A!K!!
!g!F!D!Y!
!!P!E!L!!
!f!O!M!Z!
!!e!N!a!!
!!!d!b!!!
!!!!c!!!!
!!!!!!!!!
!!!!!!!!!
EOD

def make_map
  board = BOARD.split("\n").map{|_|_.split('')}
  map = {}
  board.each_with_index{|line, y|
    line.each_with_index{|val, x|
      if val =~/[A-Za-z]/
        map[val] = []
        map[val] << board[y-2][x]
        map[val] << board[y-1][x+1]
        map[val] << board[y+1][x+1]
        map[val] << board[y+2][x]
        map[val] << board[y+1][x-1]
        map[val] << board[y-1][x-1]
      end
    }
  }
  map
end

def solve(q)
  map = make_map
  moves = q.split('').map(&:to_i)
  moves.inject('A'){|ans,move|
    last_char = ans.split('').reverse.find{|_|_!='!'}
    ans += map[last_char][move]
  }
end

DATA.readlines.each do |line|
  no,q,a = line.split(/\s+/)
  ans = solve(q)
  print no + "\t" + ans.to_s
  puts ans == a ? ' o' : ' x'
end

__END__
0	135004	ACDABHS
1	1	AC
2	33333120	AENc!!b!M
3	0	AB