Good ideas have many parents.
R.E. Boss > -----Oorspronkelijk bericht----- > Van: Programming <programming-boun...@forums.jsoftware.com> > Namens Roger Hui > Verzonden: donderdag 24 oktober 2019 21:30 > Aan: programm...@jsoftware.com > Onderwerp: Re: [Jprogramming] Quora problem > > The "all prefixes of suffixes" (or "all suffixes of prefixes") idea was > posted by > Marshall Lochbaum in September 2011. > > http://www.jsoftware.com/pipermail/programming/2011- > September/023954.html > > 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 > > > > ------------------------------------------------------------------ > > > > ---- For information about J forums see > > > > http://www.jsoftware.com/forums.htm > > > -------------------------------------------------------------------- > > > -- For information about J forums see > > > http://www.jsoftware.com/forums.htm > > > > > ---------------------------------------------------------------------- > > For information about J forums see > http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
