Tail recursion benchmarking

gistfile1.rb

def non_tail_recursive_factorial(n)
  if n < 2
    1
  else
    n * non_tail_recursive_factorial(n-1)
  end
end

def tail_recursive_factorial(n, r = 1)
  if n < 2
    r
  else
    tail_recursive_factorial(n-1, n*r)
  end
end

time_relations = []
cur_time = Time.now
(100..1000).each do |number|
  cur_time = Time.now
  tail_recursive_factorial number
  tail_recursive_time = Time.now - cur_time

  cur_time = Time.now
  non_tail_recursive_factorial number
  non_tail_recursive_time = Time.now - cur_time
  time_relations << non_tail_recursive_time.to_f / tail_recursive_time.to_f
end

time_boost = time_relations.inject{ |sum, el| sum + el }.to_f / time_relations.size
p 'Tail call factorial spent time less at ' + time_boost.to_s