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Groups > comp.lang.c > #150121
| From | "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Reinventing the wheel. |
| Date | 2020-02-20 23:27 -0800 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <r2o0pr$1jub$1@gioia.aioe.org> (permalink) |
| References | <7ca1c103-6910-48ad-8eee-b2f47e7b1db0@googlegroups.com> |
On 2/20/2020 10:33 AM, James Kuyper wrote:
> It's reinventing the wheel time, again.
[...]
> What kind of data structure would you recommend for storing that list of
> key-location pairs?
>
Think out loud here, sorry, but you might be able to benefit from a
pairing function:
https://en.wikipedia.org/wiki/Pairing_function
Humm... The numbers can get large.
Pairing 2^9 with 2^9 = 525312
____________________
#include <stdio.h>
#include <assert.h>
unsigned long
ct_cantor_pair(
unsigned long p0,
unsigned long p1
) {
unsigned long pair = (p0 + p1) * (p0 + p1 + 1) / 2 + p1;
return pair;
}
int main(void)
{
{
unsigned long pair = ct_cantor_pair(512, 512);
printf("pair = %lu\n", pair);
}
{
printf("\n\nFin!\n");
fflush(stdout);
getchar();
}
return 0;
}
____________________
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-20 10:33 -0800
Re: Reinventing the wheel. Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-20 20:04 +0100
Re: Reinventing the wheel. Bart <bc@freeuk.com> - 2020-02-20 19:11 +0000
Re: Reinventing the wheel. David Brown <david.brown@hesbynett.no> - 2020-02-20 21:50 +0100
Re: Reinventing the wheel. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-02-20 21:01 +0000
Re: Reinventing the wheel. Bart <bc@freeuk.com> - 2020-02-20 21:34 +0000
Re: Reinventing the wheel. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-02-20 22:56 +0000
Re: Reinventing the wheel. Bart <bc@freeuk.com> - 2020-02-21 00:34 +0000
Re: Reinventing the wheel. David Brown <david.brown@hesbynett.no> - 2020-02-21 09:40 +0100
Re: Reinventing the wheel. Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-02-22 14:06 -0800
Re: Reinventing the wheel. David Brown <david.brown@hesbynett.no> - 2020-02-20 20:06 +0100
Re: Reinventing the wheel. Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-20 20:08 +0100
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-20 12:46 -0800
Re: Reinventing the wheel. already5chosen@yahoo.com - 2020-02-20 13:55 -0800
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-21 00:12 -0500
Re: Reinventing the wheel. scott@slp53.sl.home (Scott Lurndal) - 2020-02-21 16:16 +0000
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-21 09:20 -0800
Re: Reinventing the wheel. jadill33@gmail.com - 2020-02-21 10:07 -0800
Re: Reinventing the wheel. scott@slp53.sl.home (Scott Lurndal) - 2020-02-21 23:23 +0000
Re: Reinventing the wheel. Richard Damon <Richard@Damon-Family.org> - 2020-02-21 18:41 -0500
Re: Reinventing the wheel. scott@slp53.sl.home (Scott Lurndal) - 2020-02-22 16:20 +0000
Re: Reinventing the wheel. already5chosen@yahoo.com - 2020-02-22 10:33 -0800
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-22 15:00 -0500
Re: Reinventing the wheel. Richard Damon <Richard@Damon-Family.org> - 2020-02-22 15:16 -0500
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-21 08:42 -0800
Re: Reinventing the wheel. David Brown <david.brown@hesbynett.no> - 2020-02-21 18:23 +0100
Re: Reinventing the wheel. Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-02-22 17:06 -0800
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-23 06:18 -0800
Re: Reinventing the wheel. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-02-20 21:14 +0000
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-21 00:24 -0500
Re: Reinventing the wheel. "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-02-20 13:15 -0800
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-20 13:44 -0800
Re: Reinventing the wheel. "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-02-20 14:21 -0800
Re: Reinventing the wheel. "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-02-20 14:22 -0800
Re: Reinventing the wheel. Robert Wessel <robertwessel2@yahoo.com> - 2020-02-20 15:19 -0600
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-21 00:28 -0500
Re: Reinventing the wheel. "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-02-20 23:27 -0800
Re: Reinventing the wheel. "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-02-20 23:52 -0800
Re: Reinventing the wheel. jadill33@gmail.com - 2020-02-21 08:20 -0800
Re: Reinventing the wheel. Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-02-22 03:15 -0800
Re: Reinventing the wheel. already5chosen@yahoo.com - 2020-02-22 10:38 -0800
Re: Reinventing the wheel. Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-02-24 02:50 -0800
Re: Reinventing the wheel. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-02-24 16:36 +0000
Re: Reinventing the wheel. Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-02-25 04:08 -0800
Re: Reinventing the wheel. David Brown <david.brown@hesbynett.no> - 2020-02-25 13:42 +0100
Re: Reinventing the wheel. already5chosen@yahoo.com - 2020-02-25 05:00 -0800
Re: Reinventing the wheel. David Brown <david.brown@hesbynett.no> - 2020-02-26 10:53 +0100
Re: Reinventing the wheel. chad <cdalten@gmail.com> - 2020-02-26 06:51 -0800
Re: Reinventing the wheel. Anton Shepelev <anton.txt@gmail.com> - 2020-02-24 22:40 +0300
Re: Reinventing the wheel. Robert Wessel <robertwessel2@yahoo.com> - 2020-02-24 16:37 -0600
Re: Reinventing the wheel. Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-02-25 01:37 -0800
Re: Reinventing the wheel. Anton Shepelev <anton.txt@g{oogle}mail.com> - 2020-02-25 13:07 +0300
Re: Reinventing the wheel. already5chosen@yahoo.com - 2020-02-25 04:50 -0800
Re: Reinventing the wheel. Anton Shepelev <anton.txt@g{oogle}mail.com> - 2020-02-25 19:30 +0300
Re: Reinventing the wheel. already5chosen@yahoo.com - 2020-02-25 08:43 -0800
Re: Reinventing the wheel. Anton Shepelev <anton.txt@gmail.com> - 2020-02-29 01:25 +0300
Re: Reinventing the wheel. Robert Wessel <robertwessel2@yahoo.com> - 2020-02-25 15:40 -0600
Re: Reinventing the wheel. Anton Shepelev <anton.txt@g{oogle}mail.com> - 2020-02-26 13:40 +0300
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-25 11:29 -0800
Re: Reinventing the wheel. Anton Shepelev <anton.txt@g{oogle}mail.com> - 2020-02-26 13:47 +0300
Re: Reinventing the wheel. James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-26 09:32 -0500
Re: Reinventing the wheel. Anton Shepelev <anton.txt@g{oogle}mail.com> - 2020-02-26 21:26 +0300
Re: Reinventing the wheel. "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-02-22 23:32 -0800
Re: Reinventing the wheel. "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-03-07 22:22 -0800
Re: Reinventing the wheel. "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-03-07 22:38 -0800
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