<?php 
ini_set('memory_limit', '-1'); 
set_time_limit(5);
?>
<?php
//***************************************/                       Функция ArrStr
function ArrStr($string)
{
$stringa="";
foreach ($string as $k=>$v)
{
$stringa.=$v;
}
return $stringa;
}
//***************************************/
?>
<?php
//***************************************/                       Функция IMUL
function imul($slice)
{
$all=array("0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
foreach($all as $k=>$v){
if($v===$slice){ return (current($all));}
}
}
//***************************************/
?>
<?php
//***************************************/                       Функция FUNC
function func($result){
$string=ArrStr($result);
if(preg_match('{^z+$}',$string)){array_unshift($result,"0");}
if(current($result)==="z"){prev($result); func($result);}
else
{
/*echo "result befor all----";
print_r ($result);
echo "</br>";//************/
$a=array_reverse($result);
$v=current($result);
$f=array_search($v,$a);
$slice=array_slice($result,-$f-1,50,true);
$slice=array_map("Imul",$slice);
/*Echo"Slice after IMUL:------";
print_r($slice);
Echo"-------"."</br>";//*************/
$result=array_replace($result,$slice);
Echo"result befor out of function//";
print_r($result);
Echo"//"."</br>";//*/
$string=ArrStr($result);
/*echo "</br>";//*********************/
echo "</br>".memory_get_usage()."</br>";//*/
if (md5($string)==="21232f297a57a5a743894a0e4a801fc3"){echo ($string);}//bgd
else {end($result); func($result);}
}
}
//***************************************/
?>
<?php
//***************************************/                      Основная форма
$result=array("0");
echo func($result);
//***************************************/
?>

Функция при запуске с неограниченным объемом памяти и временем начинает поедать оперативку пока не съест всю... что с этим можно сделать?