Online PHP editor | refs for TPo86

<?php $answer = 1; // The Setup settype($answer, 'integer'); $s = (string) $a = &$answer; $ns = (string) $n = (isset($s[1])) ? ($a >> 1)+$s[1] : ($a >> 1)+$s[0]; $f = ((int) $ns[0] ^ (int) $s[1]); // The Riddle function riddle($a, $n, $s, $f, $ns) { if ( ($a != 0 && luhn($a)) && (!$f) && (($n | $a) == 63) && (!isset($s[2])) ) { return TRUE; } return FALSE; } // The Result if (riddle($a, $n, $s, $f, $ns)) { echo "You got the correct answer! ($a)"; } else { echo "Sorry, wrong answer. ($a)"; } function luhn($number) { settype($number, 'string'); $sumTable = array( array(0,1,2,3,4,5,6,7,8,9), array(0,2,4,6,8,1,3,5,7,9)); $sum = 0; $flip = 0; for ($i = strlen($number) - 1; $i >= 0; $i--) { $sum += $sumTable[$flip++ & 0x1][$number[$i]]; } return $sum % 10 === 0; }