gistfile1.rb

class Queue
  
  attr_accessor :data, :next, :head, :tail, :size
  
  def enqueue (data)
    @data = data
    if head.nil?
      @head = @data
      @tail = @data
      @size = 1
    else
      @tail.next = @data
      @tail = @data
      size += 1
    end
  end
  
  def dequeue
    @head = @head.next
    size -= 1
  end
end