Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.c > #385196
| From | Ben Bacarisse <ben@bsb.me.uk> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Good hash for pointers |
| Date | 2024-05-28 11:07 +0100 |
| Organization | A noiseless patient Spider |
| Message-ID | <87ikyyntae.fsf@bsb.me.uk> (permalink) |
| References | (8 earlier) <86le3wfsmd.fsf@linuxsc.com> <v2voe7$3fr50$1@raubtier-asyl.eternal-september.org> <86ed9ofq14.fsf@linuxsc.com> <v2vs40$3gflh$1@raubtier-asyl.eternal-september.org> <v317u2$3td1f$1@raubtier-asyl.eternal-september.org> |
Bonita Montero <Bonita.Montero@gmail.com> writes:
> This shows the perfect equal distribution if I take a 32 bit integer
> and multiply it by the largest 32 bit prime:
There was no need to write this program. It just illustrates a specific
example of a basic theorem where the multiplier and modulus are
co-prime.
> #include <iostream>
> #include <vector>
> #include <random>
>
> using namespace std;
>
> int main()
> {
> vector<uint8_t> buckets( 1ull << 32 );
> for( size_t b = buckets.size(); b; )
> if( !++buckets[(uint32_t)--b * 0xFFFFFFFBu % buckets.size()] )
> return EXIT_FAILURE;
> vector<size_t> loads;
> for( uint8_t ld : buckets )
> {
> if( loads.size() <= ld )
> loads.resize( ld + 1 );
> ++loads[ld];
> }
> for( size_t l = 0; size_t ld : loads )
> cout << l++ << ": " << 100.0 * (ptrdiff_t)ld /
> (ptrdiff_t)buckets.size() << "%" << endl;
> }
>
>
> Result:
>
> 0: 0%
> 1: 100%
>
--
Ben.
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar
Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-23 12:11 +0100
Re: Good hash for pointers Richard Harnden <richard.nospam@gmail.invalid> - 2024-05-23 15:37 +0100
Re: Good hash for pointers Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-05-23 15:51 -0700
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-24 00:42 +0100
Re: Good hash for pointers Kaz Kylheku <643-408-1753@kylheku.com> - 2024-05-23 20:34 +0000
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-23 15:49 -0700
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-24 00:43 +0100
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-23 16:52 -0700
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-24 01:28 +0100
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-23 18:39 -0700
Re: Good hash for pointers bart <bc@freeuk.com> - 2024-05-24 11:14 +0100
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-24 12:05 +0100
Re: Good hash for pointers "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-24 10:49 -0700
Re: Good hash for pointers "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-24 10:51 -0700
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-24 06:18 -0700
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-24 15:07 +0100
Re: Good hash for pointers scott@slp53.sl.home (Scott Lurndal) - 2024-05-24 14:51 +0000
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-25 02:49 -0700
Re: Good hash for pointers David Brown <david.brown@hesbynett.no> - 2024-05-24 17:00 +0200
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-24 17:10 +0100
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-05-24 19:27 +0300
Re: Good hash for pointers David Brown <david.brown@hesbynett.no> - 2024-05-24 09:41 +0200
Re: Good hash for pointers "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-23 17:32 -0700
Re: Good hash for pointers "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-05-23 18:59 -0700
Re: Good hash for pointers jak <nospam@please.ty> - 2024-05-24 04:09 +0200
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-24 20:28 +0200
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-24 19:57 +0100
Re: Good hash for pointers bart <bc@freeuk.com> - 2024-05-25 00:54 +0100
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-25 02:12 -0700
Re: Good hash for pointers bart <bc@freeuk.com> - 2024-05-25 12:28 +0100
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-25 11:12 -0700
Re: Good hash for pointers bart <bc@freeuk.com> - 2024-05-25 20:31 +0100
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-25 22:54 -0700
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-25 17:00 +0200
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-25 10:40 -0700
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-25 18:56 +0100
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-25 11:23 -0700
Re: Good hash for pointers Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-05-25 23:13 +0200
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-25 23:07 +0100
Re: Good hash for pointers bart <bc@freeuk.com> - 2024-05-25 23:42 +0100
Re: Good hash for pointers Richard Harnden <richard.nospam@gmail.invalid> - 2024-05-26 19:58 +0100
Re: Good hash for pointers Kaz Kylheku <643-408-1753@kylheku.com> - 2024-05-26 22:42 +0000
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-26 18:05 +0200
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-26 18:07 +0200
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-26 18:04 +0200
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-26 09:24 -0700
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-26 18:36 +0200
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-26 10:20 -0700
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-26 19:39 +0200
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-26 19:54 +0200
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-27 08:07 +0200
Re: Good hash for pointers Ben Bacarisse <ben@bsb.me.uk> - 2024-05-28 11:07 +0100
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-30 10:10 +0200
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-30 11:27 +0200
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-30 19:26 -0700
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-30 19:27 -0700
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-02 10:45 +0300
Re: Good hash for pointers "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-06-02 12:42 -0700
Re: Good hash for pointers "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-06-03 12:35 -0700
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-02 16:02 -0700
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-03 10:50 +0300
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-03 18:02 -0700
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-04 11:38 +0300
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-04 22:10 -0700
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-03 16:34 +0200
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-03 17:46 +0300
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-03 17:54 +0200
Re: Good hash for pointers bart <bc@freeuk.com> - 2024-06-03 17:24 +0100
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-03 20:16 +0300
Re: Good hash for pointers bart <bc@freeuk.com> - 2024-06-03 19:48 +0100
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-03 22:41 +0300
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-03 22:51 +0300
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-03 16:51 -0700
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-03 17:01 -0700
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-03 20:25 +0200
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-03 19:50 +0300
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-03 20:31 +0200
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-05 00:59 +0300
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-05 11:10 +0200
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-05 12:34 +0300
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-05 12:05 +0200
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-05 13:11 +0300
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-05 08:58 -0700
AES problem (was: Good hash for pointers) Michael S <already5chosen@yahoo.com> - 2024-06-05 19:51 +0300
Re: AES problem (was: Good hash for pointers) Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-05 21:24 -0700
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-05 19:59 +0300
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-05 21:40 -0700
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-06 11:00 +0300
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-06 13:35 +0300
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-26 20:06 +0200
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-05-26 20:10 +0100
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-26 20:24 +0200
csiph-web