class Customer
  attr_accessor :position # 席番号
  attr_accessor :want_toppings # 欲しいネタリスト

  def initialize(position, toppings)
    @position, @want_toppings = position, toppings
  end

  def eat(topping_name)
    index = @want_toppings.index(topping_name)
    unless index.nil?
      @want_toppings.delete_at(index)
      return true
    end
    false
  end
end


class ConveyorBeltSushiSystem
  SEAT_LENGTH = 20

  attr_accessor :dishes
  attr_accessor :customers

  def initialize
    @dishes = Array.new(self.class::SEAT_LENGTH, nil)
    @customers = Array.new(self.class::SEAT_LENGTH, nil)
  end

  def go_round
    @customers.each do |customer|
      @dishes.each do |dish|
        customer.eat(dish)
      end
    end
    @dishes.each do |dish|
      dish.move
    end
  end
end