Keycode Random Gen

<?php

$pins=6;   // number of pins
$min=1;      // min pin size
$max=5;      // max pin size
$total=5;   // number of combinations to generate

$keys=array();
for ($ln=$k=0;$k<$total;$k++) {
   do {
      $bits='';
      for ($b=0;$b<$pins;$b++)
         $bits.=mt_rand($min,$max);
      for ($i=1;$i<$pins;$i++) {
         if ($bits[$i]==$bits[$i-1])
            $bits[$i]=mt_rand($min,$max);
            if (($bits[$i-1]==$min || $bits[$i-1]==$max) &&
               ($bits[$i]==$min || $bits[$i]==$max))
                  $bits[$i]=mt_rand($min+1,$max-1);
         }
   } while (@$keys[$bits]);
   $keys[$bits]=1;
   print $bits.' ';
   if (++$ln%10==0) print "\n";
}

?>