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Re: OT: Re: Sieve of Erastosthenes optimized to the max

From	Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups	comp.lang.c++
Subject	Re: OT: Re: Sieve of Erastosthenes optimized to the max
Date	2024-08-18 19:52 -0700
Organization	A noiseless patient Spider
Message-ID	<86ttfhcjhr.fsf@linuxsc.com> (permalink)
References	(16 earlier) <861q3o5do1.fsf@linuxsc.com> <v7tdts$29195$1@dont-email.me> <868qx45v5g.fsf@linuxsc.com> <v9lbns$11alj$1@dont-email.me> <86r0aojx1m.fsf@linuxsc.com>

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Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

> Vir Campestris <vir.campestris@invalid.invalid> writes:
>
[...]

>> You seem to have spotted a pattern in the steps that I didn't - I
>> looked at the mask values, and decided it wasn't worth working out
>> which of the 8 possible sequences to use - remembering which was
>> too expensive.  But it's also (I think, I haven't coded it) to work
>> out whether you need to step 2, 4, 8 times the prime.  And that
>> would save more memory.
>
> The possible steps for mod30 are 2 or 4 or 6 times the prime.
>
>> Another thought BTW - whether it's worth storing with a larger
>> modulo - say 2*3*5*7 - not just 2*3*5 is a different decision from
>> deciding whether the steps between primes should take that into
>> consideration.
>
> My guess is that the possible steps are still just 2 or 4 or 6
> (times the prime), but I haven't checked that.

I guessed wrong.  Considered mod 210, there are

   15 steps of  2
   15 steps of  4
   14 steps of  6
    2 steps of  8
    2 steps of 10

(for a total of 48 residues) due to knocking out multiples of 7.

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Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-05-30 12:32 +0100
  Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-30 14:17 +0200
  Re: Sieve of Erastosthenes optimized to the max Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-30 19:55 +0300
    Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-31 10:17 +0200
      Re: Sieve of Erastosthenes optimized to the max Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-31 20:52 +0300
  Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-30 22:17 -0700
    Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-06-01 21:07 +0100
      Re: Sieve of Erastosthenes optimized to the max Richard Damon <richard@damon-family.org> - 2024-06-01 20:43 -0400
      Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-02 03:23 -0700
        Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-02 19:50 -0700
          Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-06-18 20:56 +0100
            Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 17:34 -0700
              Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-06-30 21:47 +0100
                Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-01 23:20 -0700
                Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-07-02 21:24 +0100
                Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-07-03 11:25 +0100
                Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-15 06:15 -0700
                Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-20 07:41 -0700
                OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-07-25 12:46 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-10 07:07 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-12 15:32 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-16 07:48 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-15 17:52 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-16 08:40 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-16 19:35 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-16 19:55 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-19 21:23 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-20 17:21 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-20 17:24 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-20 17:43 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-20 17:55 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-20 18:59 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-26 12:08 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-27 06:09 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-09-01 21:23 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-01 20:40 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-09-02 07:08 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-09-03 17:45 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-19 21:34 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max red floyd <no.spam.here@its.invalid> - 2024-08-19 21:08 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-20 21:14 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-26 09:35 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-26 08:31 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-20 19:20 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-20 19:36 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-20 19:39 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-20 20:13 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max scott@slp53.sl.home (Scott Lurndal) - 2024-08-20 20:50 +0000
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-22 17:30 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-22 18:38 +0200
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-22 21:47 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-22 21:56 +0100
                Re: OT: Re: Sieve of Erastosthenes optimized to the max red floyd <no.spam.here@its.invalid> - 2024-08-22 17:00 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-26 10:59 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-26 12:47 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-18 19:52 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-10 17:24 -0700
                Re: OT: Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-11 00:00 -0700
                Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-23 07:34 -0700

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