>> (defn fib-helper [a b]
>> (fib-helper b (+ a b)))
> This defines an infinitely recursive function. It never actually
> returns anything, so it quickly exhausts the stack. Were you trying
> for a lazy infinite sequence of fibonacci numbers?
Yes - exactly, I couldn't figure it out, even after trying the same
"algorithm" in python.. I don't like giving up on it though! I would
like to see something like this version "working" somehow. I will
probably come back to it when I have learned more.
>> (defn fib (fib-helper 0 1)) ; This doesn't work either: (defn fib (fib-
>> helper '(0 1)))
> It looks like you want to use (def fib ...) instead of (defn fib ...),
> but because of the infinitely recursive fib-helper this will not get
> you much further :)
Yes - I fixed this (or put in the empty arg list - I don't remember),
and got a heap overflow error or similar. So you were right. If I'd
seen that message before I'd have figured out there was an infinite
recursion somewhere.
> For exercise two, perhaps you should try for the traditional recursive
> definition of fib?
I finally got it working without looking at someone elses code.
(defn fib [n]
(if (<= n 1) ; if 0 or 1
n ; return same, else...
(let [n1 (fib (- n 1)) ; calculate n-1 fib
n2 (fib (- n 2))] ; and n-2
(+ n1 n2)))) ; return sum of n-1 and n-2
(println (fib 9))
I had to start with the python equivalent:
def fib(n):
if n <= 1: return n
n_1 = fib(n-1)
n_2 = fib(n-2)
return n_1 + n_2
print fib(9) # Should be 34
and translate to clojure, which hopefully is something I won't have to
do forever as I understand clojure more.
Thanks,
Craig
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Clojure" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
-~----------~----~----~----~------~----~------~--~---
