ts'(#~({.<{:)"1)(i.@!A.i.)8'
0.029197332 9048960
R.E. Boss
> -----Original Message-----
> From: programming-boun...@forums.jsoftware.com [mailto:programming-
> boun...@forums.jsoftware.com] On Behalf Of 'Pascal Jasmin' via
> Programming
> Sent: vrijdag 21 augustus 2015 19:36
> To: programm...@jsoftware.com
> Subject: Re: [Jprogramming] permutations without reverses
>
> A version that compares every element to the whole list (so far) to filter
out
> is innefficient even for perm 8
>
> reduce =: 1 : '<"_1@[ ([: u (&.>)/(>@:) ,) <@:]'
>
> (}: (|.@:[ (|.@:[ , ])^:(-.@:e.) ])reduce ,:@:{:)&.|. (i.@!A.i.)4
>
> ----- Original Message -----
> From: 'Pascal Jasmin' via Programming <programm...@jsoftware.com>
> To: Programming Forum <programm...@jsoftware.com>
> Cc:
> Sent: Friday, August 21, 2015 1:10 PM
> Subject: [Jprogramming] permutations without reverses
>
> for 3, removing the "reverse duplicates" of permutations is as easy as
taking
> the top half
>
> (i.@! A. i.) 3
> 0 1 2
> 0 2 1
> 1 0 2
> 1 2 0
> 2 0 1
> 2 1 0
>
>
> last (5) is reverse of 0. 4 is reverse of 2, and 3 reverse of 1
>
> Is there a function for producing permutations without their reverse
> included?
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