100)){ $error = "your iterations must be between 1 - 100"; }else{ $passes = $_GET['passes']; // Set number of iterations } } for ($i = 1; $i <= $passes; $i++) { // How many passes to do for ($j = $i; $j <= 100; $j += $i){ // Flip switch every x Lights if($LightsBool[$j] == 0){ $LightsBool[$j] = 1; } else if ($LightsBool[$j] == 1){ $LightsBool[$j] = 0; } } } if($error <> ""){ echo $error."

"; } echo "number of passes = ".$passes."
"; echo "Lights on and off in order - "; for ($i = 1; $i <= 100; $i++) { echo $LightsBool[$i]; if($LightsBool[$i] == 1){ $LightsOn++; } } echo "
Lights on: ".$LightsOn." Lights off: ".(100 - $LightsOn)."

"; $page = "http://".$_SERVER["SERVER_NAME"]."/".substr($_SERVER["SCRIPT_NAME"],strrpos($_SERVER["SCRIPT_NAME"],"/")+1); echo "Try another iteration By going to :".$page."/?passes=<no>
"; ?>