recursive scheme program to iterative

Question

need help on making these two recursive programs in scheme iterative? I made the recursion, but am stuck at creating an iteration for both.

question 1 - recursion

(define mylength
 (lambda (l)
   (cond
   ((null? l) 0)
     (else (+ 1 (mylength (cdr l)))))))

question 1 - iteration?

question 2 - recursion

(define mylistref
  (lambda (l index)
   (cond
   ((= index 0)(car l))
     (else
       (mylistref (cdr l) (- index 1))))))

question 2 - iteration?

You probably mean recursive vs iterative process since Scheme only has recursion to do loops. Iterative calls itself in tail position thus the resutl fo the recursion is the result of the whote thing while recursive process needs to do something with the result. Thus in your first example it needs to add afterwards and thus recursive. Your second one is a iterative process since no work is done afterwards. Do you see the difference? — Sylwester
– Sylwester, Commented Oct 26, 2016 at 13:58

Nicholas Dry · Accepted Answer · 2016-10-26 19:09:25Z

1

Scheme does not have any looping structures so your only option is to use recursion if you are traversing over some kind of data structure. You can read more about it here

answered Oct 26, 2016 at 19:09

Nicholas Dry

1171 gold badge1 silver badge10 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

recursive scheme program to iterative

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related