拆分数组但每个数组的总和不超过最大值，否则推送到下一个数组索引

Question

I have two arrays, Array 1 being a donor array which has a series of values (not necessarily equal values as in my example). Array 2 is the desired result and would store a series of sub arrays with values from Array 1 where each sub array's total sum would not exceed 25. If it does, the excess would get pushed to the next index in Array 2 where the rules would also apply.

Donor array (Array 1):

$a1=array(10,10,10,10,10,10,10,10,10,10);

Desired output (Array 2):

Array
(
    [0] => 10,10,5
    [1] => 5,10,10
    [2] => 10,10,5
    [3] => 5,10,10
)

Here the code I tried but it gets an error:

Notice: Undefined offset: 10...etc.

$a1=array(10,10,10,10,10,10,10,10,10,10);
$a2=array();
$count=count($a1);

for($i=0;$i<$count;$i++){
    $a2count=array_sum($a2);

    if($a2count>25){
        $i=$i+1;
        $a2[$i]=$a1[$i];
    }
    else{
        $a2[$i]=$a1[$i];
    }
}

print_r($a2);

I don't know what logic to implement and get result I'm looking for.

Answer 1

Here you go: The logic is not so hard. Hope it helps.

   <?php 

   $a1=array(10,10,10,10,10,10,10,10,10,10);

   $a2 = [];
   $a3 = [];

   $m = 0;

   for($i = 0; $i < count($a1); ++$i){      

        $m += $a1[$i];

        if($m > 25){

           $n = $m % 25;

           if(array_sum($a2) != 25){

               $a2[] = $n;

           }


           $a3[] = implode(',', $a2);       

           $a2 = []; 

           $m = $n;

           $a2[] = $n;


         } else{

           $a2[] = $a1[$i];

         }


   }

   $a3[] = implode(',', $a2);

   print_r($a3);

   ?>