RosettaCodeData/Task/Van-Eck-sequence/Factor/van-eck-sequence.factor

13 lines
327 B
Factor

USING: assocs fry kernel make math namespaces prettyprint
sequences ;
: van-eck ( n -- seq )
[
0 , 1 - H{ } clone '[
building get [ length 1 - ] [ last ] bi _ 3dup
2dup key? [ at - ] [ 3drop 0 ] if , set-at
] times
] { } make ;
1000 van-eck 10 [ head ] [ tail* ] 2bi [ . ] bi@