Then again, since the quora problem asked for squares of consecutive
integers, your choosing the smaller set of values was the right
choice.
The current issue seems to be about naming.
"All sets" suggests the larger intermediate value.
"All prefixes of suffixes" is valid, but maybe too specific?
I would be tempted to go with "all consecutive [sub]sequences".
Thanks,
--
Raul
On Mon, Oct 28, 2019 at 3:38 PM R.E. Boss <r.e.b...@outlook.com> wrote:
>
> Notice the difference:
>
> #L:_1(allsubsets;as;<@as2)'abcdef'
> +--+--+--+
> |64|21|21|
> +--+--+--+
>
> (as) and (as2) give only the (2!n+1) consecutive subsets, not all (2^n)
> subsets.
>
>
> R.E. Boss
>
>
> > -----Oorspronkelijk bericht-----
> > Van: Programming <programming-boun...@forums.jsoftware.com>
> > Namens 'Rob Hodgkinson' via Programming
> > Verzonden: zondag 27 oktober 2019 22:26
> > Aan: jonghough via Programming <programm...@jsoftware.com>
> > Onderwerp: Re: [Jprogramming] Quora problem
> >
> > Using RE’s and Henry’s suggestions, a slight generalisation to your #3 …
> >
> > as2=: ;(#\ <@<"1@([\) ]) ‘abcdef'
> >
> > Rob
> >
> > > On 26 Oct 2019, at 7:36 am, Skip Cave <s...@caveconsulting.com> wrote:
> > >
> > > Roger,
> > >
> > > Nice! It seems there are many different approaches:
> > >
> > > allsubsets=: #:@i.@(2&^)@# #"_1 _ ]
> > > as=.3 :';<@(<\.)\y'
> > > ;(>:i.5) (|.@[ <@{."0 1 <\) 'abcde'
> > >
> > > Even if the result is to be integers, It seems it is easier to start
> > > with literals and then convert to integers later, if at all.
> > >
> > > My next challenge is to generate all *permutations* of all subsets.
> > >
> > > Skip
> > >
> > >
> > >
> > > Skip Cave
> > > Cave Consulting LLC
> > >
> > >
> > > On Thu, Oct 24, 2019 at 1:54 PM Roger Hui <rogerhui.can...@gmail.com>
> > wrote:
> > >
> > >> allsubsets=: #:@i.@(2&^)@# #"_1 _ ]
> > >> allsubsets 'abcd'
> > >>
> > >> d
> > >> c
> > >> cd
> > >> b
> > >> bd
> > >> bc
> > >> bcd
> > >> a
> > >> ad
> > >> ac
> > >> acd
> > >> ab
> > >> abd
> > >> abc
> > >> abcd
> > >> allsubsets ;:'animal vegetable mineral'
> > >> ┌─────────┬─────────┬───────┐
> > >> │ │ │ │
> > >> ├─────────┼─────────┼───────┤
> > >> │mineral │ │ │
> > >> ├─────────┼─────────┼───────┤
> > >> │vegetable│ │ │
> > >> ├─────────┼─────────┼───────┤
> > >> │vegetable│mineral │ │
> > >> ├─────────┼─────────┼───────┤
> > >> │animal │ │ │
> > >> ├─────────┼─────────┼───────┤
> > >> │animal │mineral │ │
> > >> ├─────────┼─────────┼───────┤
> > >> │animal │vegetable│ │
> > >> ├─────────┼─────────┼───────┤
> > >> │animal │vegetable│mineral│
> > >> └─────────┴─────────┴───────┘
> > >>
> > >>
> > >>
> > >> On Thu, Oct 24, 2019 at 11:30 AM Skip Cave <s...@caveconsulting.com>
> > >> wrote:
> > >>
> > >>> I find R. E. Boss' function quite useful in many instances. I call
> > >>> it
> > >> "all
> > >>> sets". Is this a standard idiom in J? Is there a more efficient
> > >>> construction that does this? Is there a primitive that does this?
> > >>>
> > >>> as=.3 :';<@(<\.)\y' NB. All Sets
> > >>>
> > >>> as i.5
> > >>>
> > >>> │0│0 1│1│0 1 2│1 2│2│0 1 2 3│1 2 3│2 3│3│0 1 2 3 4│1 2 3 4│2 3 4│3
> > >>> 4│4│
> > >>>
> > >>>
> > >>> Skip
> > >>>
> > >>>
> > >>>
> > >>> On Thu, Oct 24, 2019 at 12:30 PM R.E. Boss <r.e.b...@outlook.com>
> > wrote:
> > >>>
> > >>>> Obviously the squares >2018 don't play any role whatsoever, so you
> > >>>> can restrict yourself to %:2018
> > >>>>
> > >>>>> a#~2018=>+/ each a=.;<@(<\.)\2^~i.>.%:2018
> > >>>> 49 64 81 100 121 144 169 196 225 256 289 324
> > >>>>
> > >>>> R.E. Boss
> > >>>>
> > >>>>
> > >>>>> -----Oorspronkelijk bericht-----
> > >>>>> Van: Programming <programming-boun...@forums.jsoftware.com>
> > >>>>> Namens Skip Cave
> > >>>>> Verzonden: donderdag 24 oktober 2019 19:12
> > >>>>> Aan: programm...@jsoftware.com
> > >>>>> Onderwerp: Re: [Jprogramming] Quora problem
> > >>>>>
> > >>>>> To me it seems that R. E. Boss provided the simplest approach.
> > >>>>> Don't know about efficiency, but the results appear instantly:
> > >>>>>
> > >>>>>> a#~2018=>+/ each a=.;<@(<\.)\2^~i.100
> > >>>>>
> > >>>>> 49 64 81 100 121 144 169 196 225 256 289 324
> > >>>>>
> > >>>>> Skip
> > >>>>>
> > >> ---------------------------------------------------------------------
> > >> -
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