Ranked array sample thingey

ranked_sample.rb

class Array
  def ranked_sample(count)
    slice_size = length / count
    count.times.reduce([]) do |a, i|
      i += 1
      to_take = i == count ? length : slice_size * i
      v = (take(to_take) - a).sample
      a << v if v
      a
    end
  end
end