Online PHP editor | refs for vqBMj

<?php $big = ['html', 'body', 'div', 'body','table', 'tbody', 'tr', 'td']; $small = ['body', 'div', 'td']; $wrong = ['td', 'body', 'div']; function isSubsequence($haystack,$needle){ if(count($needle) > count($haystack)) return false; $keys = array_keys($needle); $ptr = 0; $len = count($needle); foreach($haystack as $element){ if($ptr === $len) return true; if($needle[$keys[$ptr]] === $element) $ptr++; } return $ptr === $len; } var_dump(isSubsequence($big, $small)); var_dump(isSubsequence($big, $wrong));