#include <stdlib.h>
static unsigned long int next = 1;
int rand(void)
{
next = next * 1103515245 + 12345;
return (unsigned int)(next/(2 * (RAND_MAX +1L)) % (RAND_MAX+1L));
}
void srand(unsigned int seed)
{
next = seed;
}
next = next * 1103515245 + 12345;
1103515245,1234 5
why not 1103511234 ,54321? 2 3507
"xcm" <ku****@163.com > wrote in news:dj******** **@news.yaako.c om: #include <stdlib.h>
static unsigned long int next = 1;
int rand(void) { next = next * 1103515245 + 12345; return (unsigned int)(next/(2 * (RAND_MAX +1L)) % (RAND_MAX+1L)); }
void srand(unsigned int seed) { next = seed; }
rand and srand are functions provided by the standard library. Why are
you re-writing them?
next = next * 1103515245 + 12345;
1103515245,1234 5 why not 1103511234 ,54321?
What do you mean?
--
A. Sinan Unur <1u**@llenroc.u de.invalid>
(reverse each component and remove .invalid for email address)
xcm wrote:
<snip> next = next * 1103515245 + 12345;
<snip> 1103515245,1234 5 why not 1103511234 ,54321?
Well, why not 42 and 27?
Do some googling on PRNG and linear congruential generators.
Your question doesn't seem to be about C specifically, rather it
seems to be about a particular algorithm used to implement one
version of rand(). But the C standards don't require a specific
algorithm for rand(), and comp.lan.c is not an algorithms group.
--
Peter This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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