# Flyweight
class BigChar
  def initialize(char)
    @big_char = "#{char} expended a lot of memory"
  end

  def to_s
    "#{@big_char}"
  end
end

# FlyweightFactory
class BigCharFactory
  def initialize
    @pool = {}
  end

  # singleton
  @singleton = new
  class << self
    def get_instance
      @singleton
    end
  end
  private_class_method :new

  def get_big_char(char)
    return @pool[char] if @pool.key?(char)

    @pool[char] = BigChar.new(char)
    @pool[char]
  end
end

# Client
class BigString
  def initialize(string)
    @big_chars = []
    @big_char_factory = BigCharFactory.get_instance
    string.each_char {|c| @big_chars << @big_char_factory.get_big_char(c) }
  end

  def print
    @big_chars.each {|bc| puts(bc) }
  end
end

# main
big_string = BigString.new('12345')
big_string.print