factor/extra/math/primes/solovay-strassen/solovay-strassen.factor

31 lines
732 B
Factor

! Copyright (C) 2014 John Benediktsson
! See http://factorcode.org/license.txt for BSD license
USING: combinators kernel locals math math.extras
math.extras.private math.functions math.ranges random sequences ;
IN: math.primes.solovay-strassen
<PRIVATE
:: (solovay-strassen) ( n numtrials -- ? )
numtrials <iota> [
drop
n 1 - [1,b) random :> a
a n simple-gcd 1 > [ t ] [
a n jacobi n mod'
a n 1 - 2 /i n ^mod = not
] if
] none? ;
PRIVATE>
: solovay-strassen* ( n numtrials -- ? )
{
{ [ over 1 <= ] [ 2drop f ] }
{ [ over even? ] [ drop 2 = ] }
[ (solovay-strassen) ]
} cond ;
: solovay-strassen ( n -- ? ) 32 solovay-strassen* ;