codility之Brackets

function solution($S) {    // write your code in PHP5.5    $open_symb  = array( '{', '[', '(' );    $close_symb = array( '}', ']', ')' );    $check = array();    for($i = 0; $i< strlen($S); $i++) {        $v = $S[$i];        if (in_array($v, array_values($open_symb))) {            array_push($check, $v);        } elseif (in_array($v, array_values($close_symb))) {            $symbol = array_pop($check);            $cor_symbol = array_search($v, $close_symb);            if ($symbol !== $open_symb[$cor_symbol]) {                return  0;            }        }    }        if (!empty($check)) {        return 0;    }