 ! Copyright (c) 2008 Aaron Schaefer.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: kernel math math.ranges project-euler.common sequences sets sorting ;
+USING: kernel math math.ranges project-euler.common sequences sets sorting assocs fry ;
 IN: project-euler.023
 
 ! http://projecteuler.net/index.php?section=problems&id=23

    [1,b] [ abundant? ] filter ;

: possible-sums ( seq -- seq )
    dup { } -rot [
        dupd [ + ] curry map
        rot append prune swap rest
    ] each drop natural-sort ;

PRIVATE>


    source-023
    20161 abundants-upto possible-sums diff sum ;

! [ euler023 ] time
! 2.15542 seconds

SOLUTION: euler023
