Re: Best way to get a non-repeating random number?
Re: Best way to get a non-repeating random number?
- Subject: Re: Best way to get a non-repeating random number?
- From: Jean-Daniel Dupas <email@hidden>
- Date: Tue, 14 Apr 2009 12:56:45 +0200
Le 14 avr. 09 à 12:26, Luca C. a écrit :
2009/4/14 Uli Kusterer <email@hidden>
On 14.04.2009, at 01:44, Luca C. wrote:
You can put every (unsigned) value you want in there, though in
general it's used passing (unsigned)time(NULL) as parameter. This
way
you'll always get a different int.
No you won't. It's a *random* number generator. The seed simply
means you
get a different sequence of random numbers. However, random really
means
RANDOM. I.e. it's perfectly possible to get the same number three
times in a
row during a sequence. That would still be random.
Hmm...
Given a seed, rand() will create always the same sequences for that
seed.
But if the seeds changes all the time, you'll always get different
sequences, as it's obvious. You'll get the same sequences only if
you pass
the same seed again, otherwise you'll get some other sequences.
In practical use of rand() I have never seen what you're saying,
though
it's possible. But that doesn't imply that you'll get every time
the same
number consequentally in a sequence, that's very rare case if you use
different seeds, very rare.
Am i wrong?
--Luca C.
reading /dev/random is currently the best way to generate random
number on OS X.
http://lists.apple.com/archives/apple-cdsa/2009/Mar/msg00077.html
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