factor/extra/benchmark/beust2/beust2.factor

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1.2 KiB
Factor
Executable File

! Copyright (C) 2008 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: math math.ranges math.parser sequences kernel io locals ;
IN: benchmark.beust2
! http://crazybob.org/BeustSequence.java.html
:: (count-numbers) ( remaining first value used max listener: ( -- ) -- ? )
10 first - [| i |
[let* | digit [ i first + ]
mask [ digit 2^ ]
value' [ i value + ] |
used mask bitand zero? [
value max > [ t ] [
remaining 1 <= [
listener call f
] [
remaining 1-
0
value' 10 *
used mask bitor
max
listener
(count-numbers)
] if
] if
] [ f ] if
]
] any? ; inline recursive
:: count-numbers ( max listener -- )
10 [ 1+ 1 1 0 max listener (count-numbers) ] any? drop ;
inline
:: beust ( -- )
[let | i! [ 0 ] |
10000000000 [ i 1+ i! ] count-numbers
i number>string " unique numbers." append print
] ;
MAIN: beust