$size = count($result_sum)-1;
for ($i = $size; $i>=0; $i--) {
    for ($j = 0; $j<=($i-1); $j++)
        if ($result_sum[$j]>$result_sum[$j+1]) {
            $k = $result_sum[$j];
            $result_sum[$j] = $result_sum[$j+1];
            $result_sum[$j+1] = $k;

            $b= $result_id[$j];
            $result_id[$j] = $result_id[$j+1];
            $result_id[$j+1] = $b;
        }
}


for( $a=0; $a<=$size; $a++) {
    $k=$size-$a;
    $result_sum[$a] = $result_sum[$k];
    $result_id[$a] = $result_id[$k];
}