gistfile1.rb

class Question

  attr_accessor :question, :answer, :weight
  
  def initialize(question, answer)
    @question = question
    @answer   = answer
    @weight   = 5
  end

  def update_time(time)
    @@average_time ||= time
    if time > 5*@@average_time
      time = 5*@@average_time
    end
    @@average_time = (0.8 * @@average_time) + (0.2 * time)
  end
  
  def fail(time)
    update_time(time)
    @weight += 10
  end
  
  def win(time)
    update_time(time)
    @weight += (time - @@average_time)
    @weight -= 3 # for winning.
    # just so we don't NEVER ask this question again...
    @weight = 1 if @weight < 1
  end

end

class QuestionList
  def initialize
    @list = []
  end
  
  def <<(o)
    @list << o
  end
  
  # REALLY INEFFICIENT.
  def size
    @list.map(&:weight).inject(&:+)
  end

  # REALLY INEFFICIENT.
  def get_weighted_random
    rnd = rand(size)
    @list.each do |el|
      rnd -= el.weight
      return el if rnd <= 0
    end
  end
  
end


class Quiz

  
  def initialize(hash)
    @ql = QuestionList.new
    hash.each do |key, value|
      @ql << Question.new(key, value)
    end
  end

  def quiz(n=nil, reverse=false)
    args = reverse ? [:answer, :question] : [:question, :answer]
    if n 
      n.times { question(args) }
    else 
      loop    { question(args) }
    end
  end

  def question(args=[:question,:answer])
    q = @ql.get_weighted_random
    puts q.send(args[0])
    time_start = Time.now
    
    correct = gets.chomp.downcase == q.send(args[1]).downcase
    time = Time.now - time_start

    if correct
      puts "-------------"
      q.win(time)
    else
      puts "---: NO! :--- #{q.send(args[1])}"
      q.fail(time)
    end
  end
  
end

if __FILE__ == $0

  amino = { 
    "Alanine" => "A",
    "Valine"  => "V",
    "Leucine" => "L",
    "Isoleucine" => "I",
    "Proline" => "P",
    "Methionine" => "M",
    "Phenylalanine" => "F",
    "Tryptophan" => "W",
    "Glycine" => "G",
    "Serine" => "S",
    "Cysteine" => "C",
    "Threonine" => "T",
    "Asparagine" => "N",
    "Glutamine" => "Q",
    "Tyrosine" => "Y",
    "Aspartic Acid" => "D",
    "Glutamic Acid" => "E",
    "Lysine" => "K",
    "Arginine" => "R",
    "Histidine" => "H"
  }
  
  Quiz.new(amino).quiz(nil,true)
end