Rand_max

ke121885 · 10-04-2009, 09:23 PM

I am trying to print the value of RAND_MAX with this code:

Code:

#include <stdio.h>
#include <stdlib.h>

/*
*                       Main Function
*
*/

 main(void)
{

        printf("RAND_MAX = %d\n", RAND_MAX);
}

It is giving a number that is much larger than the 32767 that it is supposed to....any help?

smeezekitty · 10-04-2009, 09:29 PM

from a 16 bit platform are we?
RAND_MAX in linux and windows has a 32 bit value (about 2 billion)

ke121885 · 10-04-2009, 09:34 PM

Now I am supposed to use lrand48() and srand48() to see what generates....I am a little lost on this....sorry but thanks in advanced!

lutusp · 10-05-2009, 12:39 AM

Quote:

Originally Posted by ke121885

I am trying to print the value of RAND_MAX with this code:

Code:

#include <stdio.h>
#include <stdlib.h>

/*
*                       Main Function
*
*/

 main(void)
{

        printf("RAND_MAX = %d\n", RAND_MAX);
}

It is giving a number that is much larger than the 32767 that it is supposed to....any help?

Where are you getting the information about what RAND_MAX is "supposed to be"? It is what it is.

And what did the program print on your system? Didn't it occur to you that this would be useful for any meaningful reply?

32767 is 2^15-1. That is tiny by modern standards. It is virtually certain to not be the value of RAND_MAX, which is typically an unsigned value one less than the system's word length -- for a 32-bit machine that would be:

2^32-1 = 4294967295

Or, for a 64-bit machine:

2^64-1 = 18446744073709551615

smeezekitty · 10-05-2009, 01:30 AM

on a 16 bit machine it is 32767
on a 32 bit machine it is 2147483647
on a 64 bit machine it is god knows what