php fill spaces of array based on values of other arrays-CodePudding

i have this problem (php).

i have an array that rapresent a pallet of 265 cm (size). i need to put into this array more pack (rapresent with other array that has size, for example 50cm, 45, cm, 30 cm,...).

how is possible to create dinamically a system that create multiple array that rapresents pallets with the best space optimization?

this is my code:

            for ($i=0; $i < $mix_cc; $i  ) { 

                foreach ($sh_array as $key => $row) { 

                    $cm_remaining = $default_cc_height_fa - $sh_size;
                    $sh_size = $sh_size   $row['size'];                          
               
                    if ($row['size'] < $cm_remaining) {
                        $mix_cc_array[$cc_number][$key] = $sh_array[$key];                   
                    } else {
                        $mix_cc_array[$cc_number   1][$key] = $sh_array[$key];             
                    }

                    unset($sh_array[$key]);
                    
                }
                $cc_number  ;   
            }

CodePudding user response：

To optimize the space in the pallets, you can try the following First Fit Decreasing (FFD) approach:

Sort the array of packs by size in descending order. This way, you can start by adding the largest packs first and try to fit as many of them as possible in the pallet.

Iterate through the sorted array of packs and try to fit each pack in the current pallet. If the pack fits, add it to the pallet; If the pack does not fit, create a new pallet and add the pack to it.

Here's some sample code that demonstrates how you can implement this approach:

$default_cc_height_fa = 265; // size of the pallet in cm
$sh_array = [50, 45, 30, 60, 70, 80]; // array of packs

// sort the array of packs in decreasing order of size
usort($sh_array, function($a, $b) {
    return $b - $a;
});

// initialize the array of pallets
$mix_cc_array = [];

// iterate through the array of packs
foreach ($sh_array as $pack) {
    // try to fit the pack into an existing pallet
    $packed = false;
    foreach ($mix_cc_array as &$pallet) {
        if ($pack <= $default_cc_height_fa - array_sum($pallet)) {
            $pallet[] = $pack;
            $packed = true;
            break;
        }
    }
    // if the pack does not fit into any existing pallet, create a new one
    if (!$packed) {
        $mix_cc_array[] = [$pack];
    }
}

print_r($mix_cc_array);

Sandbox Example: https://onlinephp.io/c/45ca2

This should give you an array of pallets that are optimally packed in terms of space utilization using the First Fit Decreasing (FFD) method. You can also look into the Next Fit Decreasing (NFD) method if this one doesn't work for you.