Mail Archives: djgpp/1999/05/19/18:57:47
Dlanor Blytkerchan wrote:
>
> >On Tue, 18 May 1999, Ronald Landheer wrote:
> >> In libc, there is some reference to random() not being all that random.
> >No, it's random even more than rand().
> Then it was the other way around ;-)
> What I don't understand is why it would be diffirent at all, if both use
> the RNG (random number generator), or does one use the RNG and the other an
> array of randomly picked integers? I've seen some programs that implement
> their own RNG code to make sure random numbers are the same on every
> computer (in VGA Planets, this is important for battle outcome to be the
> same on the host- and player-side computer, so the player can watch the
> battle). Does either rand() or random() do something similar (that you know
> of - don't download and check the source on my account ;-> )
There is no such thing as "the" random number generator. RNG just
refers to an algorithm; those used by `rand' and `random' are
different. `rand' uses a simple linear congruential random number
generator. `random', however, can use a similar algorithm or any of
several more complex ones (see `initstate' to try them). Even a glance
at the source will show it: rand.c is 23 lines, random.c is 365.
`random' is apparently more random, but due to a variety of confusing
legal issues, nobody is quite sure if we can use its code for `rand',
and so to be safe the two different RNG's remain.
--
Nate Eldredge
nate AT cartsys DOT com
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