Krautspace/project-euler
Archived
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

changed file and folder names to a sane scheme

Browse source
This commit is contained in:
ikselven 2017-07-12 00:08:34 +02:00
parent c19129e6dd
commit b725343392
34 changed files with 44 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

22
e0047/euler0047.rkt Normal file
View file

@ -0,0 +1,22 @@
#lang racket
(require math/number-theory)
(define (primefactors x)
(if (prime? x)
(list x)
(for/or ((i (cons 2 (range 3 (+ 1 (ceiling (sqrt x))) 2)))
#:when (prime? i)
#:when (zero? (remainder x i)))
(cons i (primefactors (quotient x i))))))
(define (recur x)
(if (and
(equal? (length (remove-duplicates (primefactors x))) 4)
(equal? (length (remove-duplicates (primefactors (+ x 1)))) 4)
(equal? (length (remove-duplicates (primefactors (+ x 2)))) 4)
(equal? (length (remove-duplicates (primefactors (+ x 3)))) 4))
x
(recur (+ x 1))))
(recur 2)