[Jprogramming] Another Quora problem

['Skip Cave' via Programming]

Thanks for the several nice solutions to the Quora problem. On Quora, most
of the solutions to this type
of problem are like Mike Day's approach, where they use logic to finesse
the answer.

I prefer the "brute force" approach, listing and eliminating candidates in
bulk. J's array-handling primitives
makes this style of solution fairly straightforward, and I don't have to
spend time analyzing and thinking
about multiples, factors, etc.

Raul's solution is perfect: brutish & short - and elegant. The conversion
of binary to decimal was a cool way to
solve the "by 60 and not by 24" problem that I was struggling with. Then
using I. to avoid the copy (#-binary select)
operation that I would have used, gave me a new option for solving these
types of problems.

Skip

Skip Cave
Cave Consulting LLC

On Tue, Dec 19, 2017 at 1:25 PM, Raul Miller <rauldmiller at gmail.com> wrote:

> Here's one approach:
>
>    I.1=#.|:0=24 60 |/i.1001
> 60 180 300 420 540 660 780 900
>
> Thanks,
>
> --
> Raul
>
>
> On Tue, Dec 19, 2017 at 1:52 PM, 'Skip Cave' via Programming
> <programming at jsoftware.com> wrote:
> > How many numbers from 1 to 1000 are divisible by 60 but not by 24?
> >
> > Here's my somewhat inelegant explicit solution:
> >
> >     #e=.c#~d=.-.0=24|/c=.a#~b=.0=60|/a=.1+i.1000
> >
> > 8
> >
> >
> > NB. What are the numbers?
> >
> >     e
> >
> > 60 180 300 420 540 660 780 900
> >
> >
> > How would I construct  a more compact tacit solution?
> >
> >
> > Skip
> >
> > Skip Cave
> > Cave Consulting LLC
> > ----------------------------------------------------------------------
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