My solution for 'signature' was
[:{.@/:~ {:@$ [\ (,}:)
R.E. Boss
> -----Oorspronkelijk bericht-----
> Van: Programming <[email protected]>
> Namens Roger Hui
> Verzonden: woensdag 13 februari 2019 18:16
> Aan: [email protected]
> Onderwerp: Re: [Jprogramming] nubsieve modulo rotation
>
> For each row, find a "signature", then find the nub sieve of the signatures.
> The signature I use here is the minimum of all possible rotations.
>
> signature=: {. @ (/:~) @ (i.@# |."0 1 ])
>
> ~: signature"1 a
> 1 1 1 1 1 0 1 1 1 1 1 0
>
>
>
>
> On Wed, Feb 13, 2019 at 8:55 AM R.E. Boss <[email protected]> wrote:
>
> > Let the 12 x 20 matrix be defined by
> > a=: 0 : 0
> > 1 4 4 1 _4 _4 1 1 _4 _1 _1 _4 _4 _1 4 4 _1 _1 4 1
> > 1 4 4 1 _4 _4 1 1 _4 _1 _1 _4 _4 _1 4 1 4 _1 _1 4
> > 1 4 4 1 _4 _1 _4 1 1 _4 _1 _4 _4 _1 4 1 4 _1 _1 4
> > 4 1 1 4 _1 4 1 _4 _4 1 _4 _1 _1 _4 1 _4 _1 4 4 _1
> > 4 1 1 4 _1 4 1 _4 _4 1 1 _4 _1 _1 _4 _4 _1 4 4 _1
> > _1 4 1 1 4 4 1 _4 _4 1 1 _4 _1 _1 _4 _4 _1 4 4 _1
> > _1 4 4 _1 _4 _4 _1 _1 _4 1 1 _4 _4 1 4 4 1 1 4 _1
> > _1 4 4 _1 _4 _4 _1 _1 _4 1 1 _4 _4 1 4 _1 4 1 1 4
> > _1 4 4 _1 _4 1 _4 _1 _1 _4 1 _4 _4 1 4 _1 4 1 1 4
> > 4 _1 _1 4 1 4 _1 _4 _4 _1 _4 1 1 _4 _1 _4 1 4 4 1
> > 4 _1 _1 4 1 4 _1 _4 _4 _1 _1 _4 1 1 _4 _4 1 4 4 1
> > 1 4 _1 _1 4 4 _1 _4 _4 _1 _1 _4 1 1 _4 _4 1 4 4 1
> > )
> >
> > Required is the nubsieve for the items modulo rotation.
> > So two arrays are considered to be equal if one is a rotation of the other.
> >
> > The answer I found is
> > 1 1 1 1 1 0 1 1 1 1 1 0
> >
> >
> > R.E. Boss
> > ----------------------------------------------------------------------
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> http://www.jsoftware.com/forums.htm
> ----------------------------------------------------------------------
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