PHP，数组重构，啊啊啊啊啊啊

 //原数组
$arr = [
    [
        'id'=>1,
        'shop'=>1,
        'name'=>'娃哈哈',
        'price'=>2
    ],
    [
        'id'=>2,
        'shop'=>1,
        'name'=>'法式小面包',
        'price'=>1
    ],
    [
        'id'=>3,
        'shop'=>1,
        'name'=>'火腿肠',
        'price'=>2
    ],
    [
        'id'=>4,
        'shop'=>2,
        'name'=>'伊利纯牛奶',
        'price'=>2
    ],
    [
        'id'=>5,
        'shop'=>2,
        'name'=>'煎鸡蛋',
        'price'=>2
    ],
    [
        'id'=>6,
        'shop'=>3,
        'name'=>'康师傅红烧牛肉面',
        'price'=>5
    ]
];
//重构后
$res = [
    [
        'shop'=>1,
        'price'=>5
    ],
    [
        'shop'=>2,
        'price'=>4
    ],
    [
        'shop'=>3,
        'price'=>5
    ]
];

求教，谢谢

$res = refactor($arr);


//重构
function refactor($arr){
    //数组提纯
    $arr = refine($arr);

    //获取所有shop数组并去重
    $shop = getShop($arr);

    $res = [];
    foreach ($shop as $k => $v) {
        $res[$k]['shop'] = $v;
        //根据shop累加price
        $res[$k]['price'] = getPrice($v,$arr);   
    }
    return $res;

}

//数组提纯用于循环时减少损耗
function refine($arr){
    $res = [];
    foreach ($arr as $k => $v) {
        $res[$k]['shop'] = $v['shop'];
        $res[$k]['price'] = $v['price'];
    }
    return $res;
}


//获取所有shop数组并去重
function getShop($arr){
    $shop_arr = [];
    foreach ($arr as $k => $v){
        array_push($shop_arr,$v['shop']);
    }
    $shop_arr = array_unique($shop_arr);
    return $shop_arr;
}

//根据shop累加price
function getPrice($shop,$arr){
    $price = 0;
    foreach ($arr as $k => $v){
      if($shop == $v['shop']){
          $price += $v['price']
      }
    }
    return $price;
}