Andy Hassall wrote:

On 17 Jul 2006 12:49:33 -0700, "AP"

<me**********@greenixsolutions.comwrote:

>Any suggestions on the most efficient way to generate a random number

from a range that will not return values specified in an array?

Depends how many values you have in the array compared with the

overall range of random numbers. If the number of values is small and

the random value range large, a simple "try-check array-retry as

necessary" loop is likely to be the most practical approach -

although it'll degrade in performance as the proportions of the two

change and a significant percentage of the range is marked as "used".

Hmmz, you've got a point.

If the second case:

function get_rand_except($start,$end,$not){

if(!is_array($not) || empty($not)) return mt_rand($start,$end); //we

don't bother when $not is empty....

$values = range($start,$end); //numbers in range

$choosable = array_diff($values,$not); //remove unwanted numbers

if(count($choosable)==0) return false; //check wether we can choose

anything

$choosable = array_value($choosable): //to reset array keys

return $choosable[mt_rand(0,count($choosable)-1]; //return by random key

}

Grtz,

--

Rik Wasmus