note 56146 deleted from function.rand by felipe

Note Submitter: Pierre C. ---- I am sorry to tell you this, mark at mmpro dot de, but the function you mentioned looks awfully and unnecessarily slow to me: At each iteration, you have to check if the generated number is not already in the list, so you end up with a complexity of O(n²)... at best! (In the worst case, the algorithm might just run forever!!!) ---- Here is a better (and safer!) way to generate a random array of different numbers: - First generate an array, each element filled with a different value (like: 1,2,3,4,5,...,n) - Then shuffle your array. In other words, swap each element in your array with another randomly-chosen element in the array. Now the algorithm has a complexity of O(n), instead of the original O(n²). ---- The generation of the array of values is left at the discretion of the programmer (it is down to his/her needs to determine how the values should be reparted). The shuffling of the array should go like this (WARNING: CODE NOT TESTED !!!): $length = count($array) ; for($i=0; $i<$length; $i++) { // Choosing an element at random $randpos = rand(0, $length-1) ; // Swapping elements $temp = $array[$randpos] ; $array[$randpos] = $array[$i] ; $array[$i] = $temp ; } return $array ;