I believe that the general case would be:
Design a J verb that will generate all possible unique strings of a
specific fixed length using only specified set of symbols, where each
generated string has no repeated symbols.
x gen y
Where x specifies a set of symbols (characters, numbers), and y specifies
the symbol string length (this length must be the same or less than the
number of symbols)
'12ab' gen 3
12a 12b 1a2 1b2 1ab 1ba 21a 21b 2a1 2b1 a12 a21 a1b a2b b12 b21 .....
Then one could really test algorithm efficiency using large symbol sets and
large string lengths.
Skip
Skip Cave
Cave Consulting LLC
On Tue, Aug 15, 2017 at 11:32 AM, Don Guinn <dongu...@gmail.com> wrote:
> For really big problems you could go to a larger base than 10 like
> hexadecimal. Or even bigger using more letters.
>
> On Tue, Aug 15, 2017 at 10:10 AM, Raul Miller <rauldmil...@gmail.com>
> wrote:
>
> > To compare them for equality you need to sort them.
> >
> > However, the task was to generate the integers.
> >
> > (If the example list of numbers was a part of the specification then
> > we probably should not be considering seven digit integers as
> > relevant.)
> >
> > Thanks,
> >
> > --
> > Raul
> >
> > On Tue, Aug 15, 2017 at 10:37 AM, Arie Groeneveld
> > <agroeneveld...@gmail.com> wrote:
> > > To compare both you need to do the following:
> > >
> > > 10 ts 'R=./:~,10#.(perms 7){"1/1+7 comb 9'
> > > 0.0288779 2.4132e7
> > > 10 ts 'G=.,10 #. ((],"1 0 -."1)^:6 ,.)1+i.9'
> > > 0.0258377 2.30737e7
> > > R-:G
> > > 1
> > >
> > > Looks like a draw.
> > >
> > >
> > > Op 15-08-17 om 16:16 schreef Raul Miller:
> > >>
> > >> I cannot comment on elegance, but I can disagree about the efficiency
> > >> issue:
> > >>
> > >> timespacex ',10#.(perms 7){"1/1+7 comb 9'
> > >> 0.015591 2.15104e7
> > >> timespacex '10 #. (,/@:(],"1 0 -."1)^:6 ,.)1+i.9'
> > >> 0.036695 3.7755e7
> > >>
> > >> Thanks,
> > >>
> > >
> > > ----------------------------------------------------------------------
> > > 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
