Achieve 921 and 999 by 39 loops as whole numbers - php

Question

I am in a situation where I need to achieve divide 921/39 and by giving whole numbers (39 times for loop), achieve 921 again.
$packagesCount = count($packages); // = 39
$averageWeight = 921/$packagesCount; // = 23.6153846154
foreach ($packages as $package) {
$package['Weight'] = "<whole number>";
}
The reason is, I need to give the api whole numbers but the total should be 921. Thus, I can't give round numbers.
One way I thought of is:
$packagesCount = count($packages); // = 39
$averageWeight = 921/$packagesCount; // = 23.6153846154
$remainder = ceil($averageWeight); // = 24
foreach ($packages as $package) {
$package['Weight'] = floor($averageWeight);
if ($remainder > 0) {
$package['Weight'] += 1;
$remainder -= 1;
}
}
But trying it with 999 total weight doesn't work with this approach; instead of 999 in the end, it gives 39 * 25 + 26 = 1001.
For 999, I should use 39 * 25 + 24 = 999 but how?

Answer 1

I think you need intdiv and modulo %:
$packagesCount = count($packages);
$averageWeight = $totalWeight/$packagesCount;
$wholeWeight = intdiv($totalWeight,$packagesCount);
$weightRest = $totalWeight % $packagesCount;
// totalWeight = wholeWeight * packagesCount + weightRest
$i = 0;
foreach ($packages as $key => $package) {
$w = $wholeWeight;
if ($i < $weightRest) {
$w += 1;
}
$i+= 1;
$packages[$key]['Weight'] = $w;
}
The idea is that each package while have at least intdiv weight and first weightRest packages will have +1 to their weight. In such a way you will exactly match your totalWeight.
See also an online demo
P.S. PHP is not my language so the code might be very non-idiomatic. Still I hope it conveys the idea.