关于日常收费计算的代码逻辑（php）,该怎么处理

关于日常收费计算的代码逻辑（php）
假设，有A,B,C三个人住在一起，需要开发一个网站来记录他们日常花费，比如买菜等等。那么数据表该怎么设计呢？另外这些数据怎么运算到每个人总共要付出多少钱呢？
以下是我的代码：
//$aData里面的每个数组表示每天的消费记录, money:当天总费用， mean：人均费用 ，其他的表示 用户名 ： 1/0/-1 付钱人/不用付/要付钱人
$aData = [
['money' => 30, 'mean'=> 10, 'twl' => 1, 'xxx' => -1, 'yyy' => -1],
['money' => 10, 'mean'=> 5, 'twl' => -1, 'xxx' => 1, 'yyy' => 0],
];
$count = 0;
$aList = [];
foreach($aData as $val){
foreach($val as $k => $v){
if($k == 'money'){
$count += $val['money'];
}elseif($k != 'mean' && $k != 'boss'){
$aList[$k][] = [
'out' => $v > 0 ? $val['money'] : 0, //表示自己付出的钱
'in' => $v < 0 ? $val['mean'] : 0, //表示自己要给分担的钱
'who' => $val['boss'],
];
}
}
}

$aData = [];
foreach($aList as $k => $v){
$in = $out = 0;
foreach($v as $key => $val){
$in += $val['in'];
$out += $val['out'];
}
$aData[$k] = [
'out' => $out,
'in' => $in,
];
}

结果是

这样还是不能知道 到底谁付钱给谁。求教
------解决思路----------------------
你可以一笔一笔的算

$aData = [
 ['money' => 30, 'mean'=> 10, 'twl' => 1, 'xxx' => -1, 'yyy' => -1],  
  ['money' => 30, 'mean'=> 10, 'twl' => -1, 'xxx' => -1, 'yyy' => 1], 
 ['money' => 10, 'mean'=> 5, 'twl' => -1, 'xxx' => 1, 'yyy' => 0],
 ['money' => 20, 'mean'=> 10, 'twl' => 0, 'xxx' => 1, 'yyy' => -1],
 ['money' => 20, 'mean'=> 10, 'twl' => 0, 'xxx' => 1, 'yyy' => -1],
 ['money' => 20, 'mean'=> 10, 'twl' => 0, 'xxx' => 1, 'yyy' => -1],
];
foreach($aData as $id=>$m) {
  $u = array_diff_key($m, ['money' => 0, 'mean' => 0]);
  arsort($u);
  foreach($u as $k=>$v) {
    if($v == 0) continue;
    if($v == 1) {
      $boss = $k;
      $r[$k][] = ['id' => $id, 'out' => $m['money']];
    }else {
      $r[$k][] = ['id' => $id, 'out' => $m['mean'], 'boss' => $boss];
      $r[$boss][] = ['id' => $id, 'in' => $m['mean'], 'boss' => $k];
    }
  }
}
print_r($r);

Array
(
    [twl] => Array
        (
            [0] => Array
                (
                    [id] => 0
                    [out] => 30
                )

            [1] => Array
                (
                    [id] => 0
                    [in] => 10
                    [boss] => yyy
                )

            [2] => Array
                (
                    [id] => 0
                    [in] => 10
                    [boss] => xxx
                )

            [3] => Array
                (
                    [id] => 1
                    [out] => 10
                    [boss] => yyy
                )

            [4] => Array
                (
                    [id] => 2
                    [out] => 5
                    [boss] => xxx
                )

        )

    [yyy] => Array
        (
            [0] => Array
                (
                    [id] => 0
                    [out] => 10
                    [boss] => twl
                )

            [1] => Array
                (
                    [id] => 1
                    [out] => 30
                )

            [2] => Array
                (
                    [id] => 1
                    [in] => 10
                    [boss] => xxx
                )

            [3] => Array
                (
                    [id] => 1
                    [in] => 10
                    [boss] => twl
                )

            [4] => Array
                (
                    [id] => 3
                    [out] => 10
                    [boss] => xxx
                )

            [5] => Array
                (
                    [id] => 4
                    [out] => 10
                    [boss] => xxx
                )

            [6] => Array
                (
                    [id] => 5
                    [out] => 10
                    [boss] => xxx
                )

        )

    [xxx] => Array
        (
            [0] => Array
                (
                    [id] => 0
                    [out] => 10
                    [boss] => twl
                )

            [1] => Array
                (
                    [id] => 1
                    [out] => 10
                    [boss] => yyy
                )

            [2] => Array
                (
                    [id] => 2
                    [out] => 10
                )

            [3] => Array
                (
                    [id] => 2
                    [in] => 5
                    [boss] => twl
                )

            [4] => Array
                (
                    [id] => 3
                    [out] => 20
                )

            [5] => Array
                (
                    [id] => 3
                    [in] => 10
                    [boss] => yyy
                )

            [6] => Array
                (
                    [id] => 4
                    [out] => 20
                )

            [7] => Array
                (
                    [id] => 4
                    [in] => 10
                    [boss] => yyy
                )

            [8] => Array
                (
                    [id] => 5
                    [out] => 20
                )

            [9] => Array
                (
                    [id] => 5
                    [in] => 10
                    [boss] => yyy
                )

        )

)