Files
retrobsd/share/example/prime.scm
2014-04-09 14:27:18 +01:00

30 lines
511 B
Scheme

(define (square n) (* n n))
(define (divides? a b)
(= (remainder b a) 0))
(define (find-divisor n test-divisor)
(cond ((> (square test-divisor) n) n)
((divides? test-divisor n) test-divisor)
(else (find-divisor n (+ test-divisor 1)))))
(define (smallest-divisor n)
(find-divisor n 2))
(define (prime? n)
(= n (smallest-divisor n)))
(define (t n)
(display n)
(if (prime? n)
(display '-prime)
(display '-compound))
(newline))
(t 2)
(t 20)
(t 23)
(t 65)
(t 67)
(t 2011)