<PRIVATE
: source-004 ( -- seq )
- 100 999 [a,b] [ 10 divisor? not ] filter ;
+ 100 999 [a,b] [ 10 divisor? ] reject ;
: max-palindrome ( seq -- palindrome )
natural-sort [ palindrome? ] find-last nip ;
PRIVATE>
: euler004 ( -- answer )
- source-004 dup cartesian-product [ product ] map prune max-palindrome ;
+ source-004 dup [ * ] cartesian-map combine max-palindrome ;
! [ euler004 ] 100 ave-time
! 1164 ms ave run time - 39.35 SD (100 trials)