yokohama.rb#49-result-proper-activities

require 'pp'

class RotateMatrix
  OFFSETS = [
    [1,0],
    [1,1],
    [0,1],
    [-1,1],
    [-1,0],
    [-1,-1],
    [0,-1],
    [1,-1]
  ]

  def initialize 
    @moved = []
    @matrix = [
      %w(a b c d e),
      %w(f g h i j),
      %w(k l m n o),
      %w(p q r s t),
      %w(u v w x y),
    ]
  end

  def execute(cmd)
    cmd.each_char do |chr|
      rotate(chr)
    end
    print_result
  end

  private
  def rotate(chr)
    @moved = select_move_cells(position(chr))
    tmp_matrix = Marshal.load(Marshal.dump(@matrix))
    @moved.rotate(rotate_direction(chr)).zip(@moved).each do |pos_pair|
      after = pos_pair.first
      before = pos_pair.last
      tmp_matrix[after.first][after.last] = @matrix[before.first][before.last]
    end
    @matrix = tmp_matrix
  end

  def position(chr)
    target = chr.downcase
    @matrix.each_with_index do |row,idx1|
      row.each_with_index do |elem,idx2|
        if elem === target then
          return [idx1, idx2]
        end
      end
    end
  end

  def select_move_cells(base)
    OFFSETS.map { |offset|
      calc_pos(base, offset)
    }.select { |pos|
      check_range(pos)
    }
  end

  def calc_pos(base, offset)
    [base.first+offset.first, base.last+offset.last]
  end

  def check_range(pos)
    (0...5).include?(pos.first) && (0...5).include?(pos.last)
  end

  def rotate_direction(chr)
    if upcase?(chr) then
      1
    else
      -1
    end
  end

  def upcase?(chr)
    chr.upcase === chr
  end

  def print_result
    # pp @matrix
    puts @moved.map{|pos| @matrix[pos.first][pos.last]}.sort.join
  end
end

if __FILE__ === $0 then
  ins = RotateMatrix.new
  ins.execute(ARGV.first)
end