A more symmetric ffib3:
ffib3=: (,+/ .*~,,:],-)/@]`((,+/ .*~,,:~[,~+)/@])@.({...@[)/@(1x 0,~,.@|....@#:)
BTW: the idea of using implicit matrix multiplication came from R.E. Boss
=@@i
Aai schreef:
> Inspired by Haskells: http://tinyurl.com/3c3yor
>
>
> ffib=:(+&*:,]*]-~+:@[)/@]`((+&*:,~[*[++:@])/@])@.({...@[)/@(1x 0,~,.@|....@#:)
>
> ffib"0 i.8
> 1 0
> 1 1
> 2 1
> 3 2
> 5 3
> 8 5
> 13 8
> 21 13
>
> ts '{: ffib 100001'
> 0.748854 265536
>
> 11{. ": {: ffib 100001
> 42026927029
>
>
> (slower) variants:
>
> ffib2=: (+&*:,+:@*-*:@])/@]`((+&*:,~*:@[++:@*)/@])@.({...@[)/@(1x
> 0,~,.@|....@#:)
>
> ffib3=: (,+/ .*~,,:],-)/@]`(((,~,:~[,+)+/ .*,~)/@])@.({...@[)/@(1x
> 0,~,.@|....@#:)
>
>
>
>
> =@@i
>
>
>
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