bstolte

class LinkedListNode
  attr_accessor :value, :next_node
 
  def initialize(value, next_node=nil)
    @value = value
    @next_node = next_node
  end
end

def print_values(list_node)

bstolte

require 'minitest/autorun'

module Luhn
  # number must be a string
  # number = number.to_s

  def self.is_valid?(number)
    array = number.to_s.split('')
    array = array.reverse
    array = array.map.with_index do |x, i|

bstolte

def collatz(n)
  length = 1
  
  loop do
    if n == 1
      return length
    end
    if n % 2 == 0
      n = n / 2
    else

bstolte

# use iteration 
def iterative_fib(n)
  fib = [1, 1]
  a = 0
  b = 1

  n.times do
    fib << fib[a] + fib[b]
    a += 1
    b += 1