From 3324327b80a50e94843dedbb704683ee9b3a9955 Mon Sep 17 00:00:00 2001 From: bd Date: Sun, 4 Aug 2024 21:01:32 -0600 Subject: Cleanup prime? --- prime?/prime.scm | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100755 prime?/prime.scm (limited to 'prime?/prime.scm') diff --git a/prime?/prime.scm b/prime?/prime.scm new file mode 100755 index 0000000..3d08a35 --- /dev/null +++ b/prime?/prime.scm @@ -0,0 +1,17 @@ +(define-module (prime)) + + +(define-public (prime? n) + "Returns #t if N is prime, else #f." + + (define (prime-helper n d) + "Recursively checks if N is a prime number +by attempting division by number D,D-1,D-2..." + (cond + ((< d 2) #t) + ((zero? (remainder n d)) #f) + (#t (prime-helper n (1- d))))) + + (if (< n 2) + #f + (prime-helper n (quotient n 2)))) -- cgit v1.2.3