class FloodFill < Array
  def initialize(data, options = {})
     data.each_line { |s| self << s.strip.split(//) }
     @options = options
  end

  def fill(x, y, target_color, replacement_color)
      return unless self[y][x]	# valid point?

      return if self[y][x] != target_color
      return if self[y][x] == replacement_color
      
      (dump; sleep(0.2)) if @options[:animation]

      self[y][x] = replacement_color
      fill(x+1, y, target_color, replacement_color)
      fill(x-1, y, target_color, replacement_color)
      fill(x, y+1, target_color, replacement_color)
      fill(x, y-1, target_color, replacement_color)  
  end
  def dump
    each { |l| puts l.join }
  end
end

data = <<END
##############
#   #        #
#   #        #
#  #      #  #
###      #   #
#        #   #
##############
END

b = FloodFill.new(data, :animation => true)

puts " START: "
b.dump

b.fill(5,3, ' ', 'O')

puts " DONE: "
b.dump