Sujet : .Re: A simple lisp problem.
De : No_spamming (at) *nospam* noWhere_7073.org (B. Pym)
Groupes : comp.lang.lispDate : 15. Jun 2024, 05:45:39
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <v4j2p1$3a0lu$1@dont-email.me>
User-Agent : XanaNews/1.18.1.6
Frank Schwieterman wrote:
I am Lisp beginner and I am doing a simple execise on lisp. I was asked
to write a lisp program , by using either recursion or do, to return
true if the difference between each successive pair of the them is 1.
>
ie:
>
(difference '(2 1))
T
(difference'(3 4 5 6 5 4))
T
(differnce '(3 4 5 3))
NIL
....
(defun difference (param)
(if (> (length param) 1)
(if (<= (abs (- (first param) (first (rest param)))) 1 )
(difference (rest param))
nil
)
T
)
)
Gauche Scheme
(define (diff1? xs)
(every
(lambda (a b) (= 1 (abs (- a b))))
xs
(cdr xs)))
(diff1? '(2 3 4 3 4 5 6 7 8 9 8))
===>
#t
(diff1? '(2 3 4 3 4 5 6 7 8 9 8 0))
===>
#f