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Groups > comp.os.linux.advocacy > #383653
| From | deplorable owl <owl@rooftop.invalid> |
|---|---|
| Newsgroups | comp.os.linux.advocacy, sci.physics |
| Subject | Re: C/CPP's "srand( int Seed )" generates an array of (PseudoRandom) int's. |
| Date | 2016-12-11 07:23 +0000 |
| Organization | O.W.L. |
| Message-ID | <ahb0a11.bu00b3@rooftop.invalid> (permalink) |
| References | (2 earlier) <ahjgob040.ae@rooftop.invalid> <o2i132$ll7$1@dont-email.me> <aybudaoc993.ag@rooftop.invalid> <o2i755$3d9$1@dont-email.me> <Jeff-Relf.Me@Dec.10--11.09P.Seattle.2016> |
Cross-posted to 2 groups.
In comp.os.linux.advocacy Jeff-Relf.Me <@.> wrote:
> You ( deplorable owl ) wrote:
>> I want to know the best approach for randomizing
>> over a huge range (far exceeding RAND_MAX) with minimal dups.
>
> C/CPP's "srand( int Seed )" generates an array of (PseudoRandom) int's;
void srand(unsigned int seed);
> i.e. it's a "Linear Congruential Generator" (LCG).
>
> The code looks like this:
> // Deal() returns a random int;
> // the first call to Deal() shuffles "the deck" ( an array of int's ).
>
> #include <Windows.H>
Don't have Windows.H here.
> #include <StdIO.H>
>
Don't have StdIO.H here either.
anon@lowtide:~/code/dfsdates$ cat foo.c
#include <StdIO.H>
int main(int argc, char *argv[])
{
return 0;
}
anon@lowtide:~/code/dfsdates$ gcc -Wall -o foo foo.c
foo.c:1:19: fatal error: StdIO.H: No such file or directory
#include <StdIO.H>
^
compilation terminated.
anon@lowtide:~/code/dfsdates$
> __int64 _Tics ;
> #define Tics ( QueryPerformanceCounter( ( LARGE_INTEGER * ) &_Tics ), _Tics )
> #define LOOP while ( 1 )
> #define Loop( N ) int J = -1, LLL = N ; while ( ++ J < LLL )
> #define LoopD( N ) int J = N ; while( -- J )
>
> const int HighResQual = 0x400, DecM = HighResQual * 4- 1
> , LongLeg = 63, Short_Leg = 37, BothLegs = LongLeg + Short_Leg
> , Seed_Buf_Sz = 2 * BothLegs - 1, StopBit = 1<<30
> , EvenBits = StopBit - 2, Rand_Mask = StopBit - 1 ;
>
> int LegsBuf[ BothLegs ], HighResBuf[ HighResQual ];
> pInt RanE = HighResBuf + BothLegs, RanP ;
> _LnP Dec = _LnP( HighResBuf );
>
> Shuffle () {
> int StreamSperation = 70 - 1, Seed_Buf[ Seed_Buf_Sz ]
> , Seed = Tics, Seed_2 = Seed + 2 & EvenBits; RanP = RanE ;
> { Loop( BothLegs ) {
> Seed_Buf[ J ] = Seed_2, Seed_2 <<= 1 ;
> if ( Seed_2 >= StopBit ) Seed_2 -= EvenBits ; } }
>
> memset( Seed_Buf + BothLegs, 0, ( BothLegs - 1 ) * szInt );
> Seed_Buf[ 1 ] ++, Seed_2 = Seed & Rand_Mask ;
> LOOP { { LoopD( BothLegs ) Seed_Buf[ 2 * J ] = Seed_Buf[ J ]; }
> { pInt P = Seed_Buf + 1, R = Seed_Buf + Seed_Buf_Sz - 1;
> Loop( BothLegs - LongLeg / 2 - 1 )
> P[ 2 * J ] = R[ -2 * J ] & EvenBits; }
> { pInt B = Seed_Buf, P = B + Seed_Buf_Sz, R = B + Short_Leg - 1 ;
> LoopD( BothLegs ) { if ( ! ( * -- P & 1 ) ) continue;
> R[ J ] = R[ J ] - * P & Rand_Mask ;
> B[ J - 1 ] = B[ J - 1 ] - * P & Rand_Mask ; } }
> if ( Seed_2 & 1 ) {
> memmove( Seed_Buf + 1, Seed_Buf, BothLegs * szInt );
> * Seed_Buf = Seed_Buf[ BothLegs ];
> if ( Seed_Buf[ BothLegs ] & 1 )
> Seed_Buf [ Short_Leg ]
> = Seed_Buf [ Short_Leg ]
> - Seed_Buf[ BothLegs ] & Rand_Mask ; }
>
> if ( ! Seed_2 && ! -- StreamSperation ) break;
> Seed_2 >>= 1 ; }
>
> memmove( LegsBuf, Seed_Buf + Short_Leg, LongLeg * szInt );
> memmove( LegsBuf + LongLeg, Seed_Buf, Short_Leg * szInt ); }
>
> int Deal() { if ( ! RanP ) Shuffle();
> if ( RanP && RanP < RanE ) return * RanP ++ ;
> RanP = HighResBuf, memmove( HighResBuf, LegsBuf, sizeof LegsBuf );
> { Loop( HighResQual - BothLegs )
> HighResBuf [ J + BothLegs ]
> = HighResBuf [ J ] - HighResBuf [ J + LongLeg ] & Rand_Mask ; }
> pInt P = HighResBuf + HighResQual - Short_Leg ;
> { Loop( Short_Leg )
> LegsBuf [ J ] = P [ J - LongLeg ] - P [ J ] & Rand_Mask ; }
> P = HighResBuf + HighResQual - LongLeg ;
> Loop( LongLeg ) LegsBuf [ J + Short_Leg ] = P [ J ] - LegsBuf [ J ] & Rand_Mask ;
> return * RanP ++ ; }
Nice ascii art.
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Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-07 12:27 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-07 19:52 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-07 21:28 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-08 05:52 +0000
Re: Where are you, sdb? I have something fun for your little morons to try chrisv <chrisv@nospam.invalid> - 2016-12-08 07:02 -0600
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 09:02 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Adlbifhr Mjduhgfks <am@random.us> - 2016-12-08 00:32 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-07 21:48 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Adlbifhr Mjduhgfks <am@random.us> - 2016-12-08 14:17 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 11:00 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-08 09:13 -0800
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 18:41 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-08 17:32 -0800
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 21:12 -0500
Cartoons are easier to read than the Wall Street Journal. Jeff-Relf.Me <@.> - 2016-12-08 20:16 -0800
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-09 09:03 -0800
Re: Where are you, sdb? I have something fun for your little morons to try Adlbifhr Mjduhgfks <am@random.us> - 2016-12-08 15:49 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 11:00 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Adlbifhr Mjduhgfks <am@random.us> - 2016-12-08 16:24 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 18:43 -0500
Only _results_ matter; i.e.: What does it do ? Jeff-Relf.Me <@.> - 2016-12-08 19:45 -0800
Re: Only _results_ matter; i.e.: What does it do ? flatfish+++ <flatfish@linuxmail.org> - 2016-12-08 22:50 -0500
I don't need the source code. Jeff-Relf.Me <@.> - 2016-12-08 20:39 -0800
Re: I don't need the source code. flatfish+++ <flatfish@linuxmail.org> - 2016-12-08 23:48 -0500
I'm hard to copy, thank God. Jeff-Relf.Me <@.> - 2016-12-08 22:30 -0800
Re: I'm hard to copy, thank God. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 01:54 -0500
Re: I'm hard to copy, thank God. Steve Carroll <fretwizzer@gmail.com> - 2016-12-09 12:30 -0800
Re: I don't need the source code. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 07:12 +0100
Re: I don't need the source code. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 01:15 -0500
Re: I don't need the source code. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 07:27 +0100
Re: I don't need the source code. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 01:44 -0500
Usenet is not CraigsList nor WikiPedia, Reddit. Jeff-Relf.Me <@.> - 2016-12-08 23:00 -0800
Re: Usenet is not CraigsList nor WikiPedia, Reddit. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 02:12 -0500
If/When Cola is being honest, they don't think MicroSoft is "Evil". Jeff-Relf.Me <@.> - 2016-12-08 23:56 -0800
Re: Usenet is not CraigsList nor WikiPedia, Reddit. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 08:16 +0100
Usually, the __DEFAULT__ "Subject:" line isn't best. Jeff-Relf.Me <@.> - 2016-12-08 22:53 -0800
Re: Usually, the __DEFAULT__ "Subject:" line isn't best. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 08:19 +0100
Please lookup the word "Default". Jeff-Relf.Me <@.> - 2016-12-08 23:31 -0800
Re: Please lookup the word "Default". Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 08:42 +0100
The parent post. -- Re: Please lookup the word "Default". Jeff-Relf.Me <@.> - 2016-12-09 00:12 -0800
Re: The parent post. -- Re: Please lookup the word "Default". Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 11:28 +0100
Threads branch like a tree, SubTopics sprout. Jeff-Relf.Me <@.> - 2016-12-09 03:35 -0800
Re: Threads branch like a tree, SubTopics sprout. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 16:18 +0100
Re: The parent post. -- Re: Please lookup the word "Default". moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-12-09 15:05 +0000
I want details, Michael Moroney. Jeff-Relf.Me <@.> - 2016-12-09 07:18 -0800
Re: I want details, Michael Moroney. Steve Carroll <fretwizzer@gmail.com> - 2016-12-09 10:38 -0800
Re: I want details, Michael Moroney. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-12-10 04:03 +0000
I never had to deal with such problems. Jeff-Relf.Me <@.> - 2016-12-09 21:15 -0800
Re: I never had to deal with such problems. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-12-11 01:50 +0000
Re: The parent post. -- Re: Please lookup the word "Default". chrisv <chrisv@nospam.invalid> - 2016-12-09 09:37 -0600
Re: The parent post. -- Re: Please lookup the word "Default". moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-12-09 20:32 +0000
Re: I don't need the source code. chrisv <chrisv@nospam.invalid> - 2016-12-09 06:39 -0600
Re: I don't need the source code. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 16:19 +0100
Re: I don't need the source code. Silver Slimer <.m@nsn.s> - 2016-12-09 11:51 -0500
Re: I don't need the source code. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 12:07 -0500
Re: I don't need the source code. Silver Slimer <.m@nsn.s> - 2016-12-09 12:22 -0500
Re: I don't need the source code. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 12:28 -0500
Re: I don't need the source code. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-12-09 17:52 +0000
I only have time to read a few select authors, sorry. Jeff-Relf.Me <@.> - 2016-12-09 10:05 -0800
Re: I don't need the source code. chrisv <chrisv@nospam.invalid> - 2016-12-09 12:26 -0600
Re: I don't need the source code. Silver Slimer <.m@nsn.s> - 2016-12-09 14:06 -0500
Re: I don't need the source code. Chris Ahlstrom <OFeem1987@teleworm.us> - 2016-12-09 19:56 -0500
Re: I don't need the source code. Silver Slimer <.m@nsn.s> - 2016-12-10 09:23 -0500
Re: Only _results_ matter; i.e.: What does it do ? fr314159@gmail.com - 2016-12-09 07:17 -0800
Re: Only _results_ matter; i.e.: What does it do ? DFS <nospam@dfs.com> - 2016-12-12 18:54 -0500
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-12 18:39 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-09 03:38 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-09 19:00 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-10 00:33 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 05:24 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-10 06:54 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 06:25 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-10 07:28 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 19:56 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 15:19 -0500
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 15:23 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 20:44 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 17:55 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 00:02 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 19:39 -0500
C/CPP's "srand( int Seed )" generates an array of (PseudoRandom) int's. Jeff-Relf.Me <@.> - 2016-12-10 23:09 -0800
Re: C/CPP's "srand( int Seed )" generates an array of (PseudoRandom) int's. deplorable owl <owl@rooftop.invalid> - 2016-12-11 07:23 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 19:56 -0500
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 20:07 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 04:07 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-11 00:18 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-11 03:40 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 04:00 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-11 05:08 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 04:27 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-11 05:58 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 05:55 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-11 07:11 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 06:49 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-11 07:52 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 07:09 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-11 08:23 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 07:37 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-11 08:40 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 09:05 +0000
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 19:41 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-10 20:48 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 20:06 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 10:32 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-10 16:40 +0100
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 11:03 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-10 09:26 -0800
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 12:38 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-10 09:52 -0800
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 13:01 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-10 10:06 -0800
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 19:38 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 19:55 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 19:33 +0000
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 20:00 +0000
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