Getting around the int limit of rand() and mt_rand().

Part of a script that I'm working on needs to call a random number from a theoretically extremely large maximum number (i.e., even upwards of 1,000^4).

If I simply call a rand(1,x) or mt_rand(1,x), it actually starts sending back negative numbers (overflow).

The actual line of code is simple (using 1000 as an example):

$totalcount = 1000;
$random = rand(1,pow($totalcount,4));

Is there a way to either increase the maximum number to randomize or to work around it somehow?

Thanks!
- Submerged

 

Hmmmm . . . I did find one possible solution:

$totalcount = 1000;
$random = mt_rand() / (double)mt_getrandmax()); // Gives a random decimal between 0 and 1
$random = $random * bcpow("$totalcount",'4',2)); // Multiplies that decimal by the exponent -- i.e., gives a number between 1 and $totalcount^4, though with additional decimals.
$random = ceil($rand); // Gets rid of extra decimals. Could also round() or floor() depending on purpose.

This seems efficient enough, unless someone has something better?

 

<?php

$base	= 1000;
$pow	= 12;
$bpow	= bcpow($base, $pow);
$len	= strlen($bpow);
$rand	= substr(lcg_value(), 2);
while(strlen($rand) < $len)
{
	$rand .= substr(lcg_value(), 2);
}
$rand = "0.$rand";

echo bcmul($rand, $bpow, 0);
echo PHP_EOL;

?>

Code (markup):

 

define ("DESIRED_LENGTH", 50); //length of our random number
$ctr = 0;
$output = "";
while ($ctr < DESIRED_LENGTH)
{
$output .= rand(0, 9);
$ctr++;
}
echo $output;

 

Haha . . . that is so simple it's brilliant . Thanks!