Skip to content

Instantly share code, notes, and snippets.

@zeptometer

zeptometer/57.scm

Created November 29, 2013 13:56
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save zeptometer/7706035 to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save zeptometer/7706035 to your computer and use it in GitHub Desktop.
Download ZIP
Raw
57.scm
(define (fib2 n)
(let loop ((stack (list n)) (ans 0))
(if (null? stack)
ans
(let ((top (car stack)))
(cond ((= top 0) (loop (cdr stack) ans))
((= top 1) (loop (cdr stack) (+ ans 1)))
(else (loop `(,(- top 1) ,(- top 2) ,@(cdr stack)) ans)))))))
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment