PHP Packing Solution - How to divide items equally

This tutorial concept is actually come from stackoverflow where the solution was suggested in ruby script but I had translate it in PHP script.

$list_of_bags = array(11, 41, 31, 15, 15, 66, 67, 34, 20, 42, 22, 25);
# total weight of all bags
$weight_of_bags = array_sum($list_of_bags);
# how many containers do we have at our disposal?
$number_of_containers = 4;
# How much should one container weight?
$weight_per_container = $weight_of_bags / $number_of_containers;
# We make an array containing an empty array for each container
$containers[] = array();

$total = 0;

# For each bag
foreach ($list_of_bags as $bag) {
    for($i=0; $i<$number_of_containers; $i++){

        $total = (isset($containers[$i])) ? array_sum($containers[$i]) : 0;
        if($total + $bag < $weight_per_container){
            $containers[$i][] = $bag;
            break;
        }
    }
}

# output all containers with the number of items and total weight
foreach ($containers as $index=>$container) {
   echo "container $index has ";
   echo count($container);
   echo " ";
   echo "items and weigths: ";
   echo array_sum($container);
   echo "
";
}

Output:
container 0 has 3 items and weigths: 83
container 1 has 3 items and weigths: 96
container 2 has 2 items and weigths: 87
container 3 has 2 items and weigths: 76
container 4 has 2 items and weigths: 47