Arrange array and delete duplicate values - php

Question

I'm stuck with a tricky task I can't solve without the code being very messy with a lot of foreach loops.
This is the fundamental logic:
There can only be unique foods in the array, so only one guy can have Pizza, only one guy can have Pasta etc. But they can have multiple foods. And the guy with the most foods in the array, should win the foods over the ones with few foods.
So John should be deleted from the array since either Joe or Conny will have his.
And since Joe and Conny have the same amount of foods, one of them will keep all of his foods and the other one should be deleted from the array and it should be picked randomly whether it is Joe or Conny.
The starting array looks like this:
Array
(
[Joe] => Array
(
[0] => Pizza
[1] => Pasta
[2] => Lasagne
[3] => Tacos
[4] => Hamburger
)
[Conny] => Array
(
[0] => Pizza
[1] => Pasta
[2] => Lasagne
[3] => Tacos
[4] => Hamburger
)
[John] => Array
(
[0] => Pizza
[1] => Pasta
)
[Fred] => Array
(
[0] => Pizza
[1] => Pasta
[2] => Soup
[3] => Fish
)
[Greg] => Array
(
[0] => Sushi
)
)
And the end result I want is:
Array
(
[Joe] => Array
(
[0] => Pizza
[1] => Pasta
[2] => Lasagne
[3] => Tacos
[4] => Hamburger
)
[Fred] => Array
(
[2] => Soup
[3] => Fish
)
[Greg] => Array
(
[0] => Sushi
)
)
So only unique foods left in the array and if two or more guys have the same amount, it should randomly pick whether of these should keep the foods.
Any suggestions how I can do this?

Answer 1

You have to first sort the array depending on the count of elements in the subarray in reverse order using an user-defined function with uasort. Then you can use two foreach loops to loop through the loop. You will use a helper variable to determine if a food has already been used and if so unset the element. After doing that you filter out the empty elements in the array with array_filter.
uasort($food, function($a, $b) {
return count($b) <=> count($a);
});
$used = array();
foreach($food as $kl => $pl) {
foreach($pl as $k => $p) {
if(!in_array($p, $used)) {
$used[] = $p;
} else {
unset($food[$kl][$k]);
}
}
}
$food = array_filter($food);
You can see it here: https://3v4l.org/LjpGD
Reference:
http://php.net/uasort
http://php.net/in_array
http://php.net/array_filter
PS: The code uses the new since PHP 7.0 available spaceship operator. If you don't or can't use PHP7, you have to use an if construct as below for comparison.
if(count($b) > count($a)) {
return 1;
} elseif(count($b) == count($a)) {
return 0;
} else {
return -1;
}