Ruby Conjectura de Collatz

Conjectura.rb

class Conjectura
  attr_reader :elements
  
  def initialize
   @elements = Hash.new
  end
  
  def calc(range)
    range.each{ |i| calc_seq_cache i }
  end
  
  def calc_seq_cache(n)
    @elements[n] = calc_seq(n,1)
  end
  
  def calc_seq(n,s)
    if @elements[n]
      return @elements[n] + s -1
    elsif n == 1
      return s
    elsif n & 1 == 0
      return calc_seq(n/2,s+1)
    else
      return calc_seq(3*n+1,s+1)
    end
  end
end

conjectura_spec.rb

require 'spec_helper'
require 'benchmark'

describe Conjectura do
  it 'do calc 999.999 get hightest sequence' do
    conjectura = Conjectura.new
    Benchmark.bm do |x|
      x.report { conjectura.calc(1..999_999) }
    end
    expect(conjectura.elements.values.max).to eq(525)
  end
end

spec_helper.rb

require_relative '../lib/conjectura'
 
require 'yaml'