Fibonacci sequence in Ruby (recursion)

Question

I\'m trying to implement the following function, but it keeps giving me the stack level too deep (SystemStackError) error.

Any ideas what the problem mi

Answer 1

Joining the Fibonacci train:

Regular:

def fib(num)
  return num if (num < 2) else fib(num-1) + fib(num-2)
end

With caching:

module Fib
  @fibs = [0,1]
  def self.calc(num)
    return num if (num < 2) else @fibs[num] ||= self.calc(num-1) + self.calc(num-2)
  end
end