! Copyright (c) 2008 Eric Mertens.
! See http://factorcode.org/license.txt for BSD license.
-USING: fry kernel math math.primes.factors sequences sets project-euler.common ;
+USING: kernel math math.primes.factors math.vectors sequences sets
+project-euler.common ;
IN: project-euler.203
! http://projecteuler.net/index.php?section=problems&id=203
swapd '[ @ dup ] replicate nip ; inline
: (generate) ( seq -- seq )
- [ 0 prefix ] [ 0 suffix ] bi [ + ] 2map ;
+ [ 0 prefix ] [ 0 suffix ] bi v+ ;
: generate ( n -- seq )
- 1- { 1 } [ (generate) ] iterate concat prune ;
+ 1 - { 1 } [ (generate) ] iterate union-all ;
: squarefree ( n -- ? )
factors all-unique? ;