0xD34F

function getRootItem($id, $array) {
  foreach ($array as $item) {
    if ($item['id'] === $id) {
      $parent = $item['parent'];
      return $parent === 0 ? $item : getRootItem($parent, $array);
    }
  }

  return null;
}

$grouped = [];

foreach ($array as $item) {
  $grouped[$item['name']][] = $item;
}

preg_match_all('/[A-Z]+ - \d+(,\d+)?/', $str, $matches);
$data = array_map(function($n) {
  $d = explode(' - ', $n);
  return [
    'size' => $d[0],
    'value' => $d[1]
  ];
}, array_unique($matches[0]));

function walk($data, $key, &$result) {
  foreach ($data as $k => $v) {
    if (!array_key_exists($k, $result)) {
      $result[$k] = [];
    }

    if (!is_array($v) || array_keys($v) === range(0, count($v) - 1)) {
      $result[$k][$key] = $v;
    } else {
      walk($v, $key, $result[$k]);
    }
  }
}

function merge(...$arrays) {
  $result = [];

  foreach ($arrays as $arr) {
    $key = array_keys($arr)[0];
    walk($arr[$key], $key, $result);
  }

  return $result;
}

$result = merge($array1, $array2);

$merged = [];
foreach ($arr as $item) {
  $key = $item['id_user'].'/'.$item['price'];
  if (array_key_exists($key, $merged)) {
    $merged[$key]['count'] += $item['count'];
  } else {
    $merged[$key] = $item;
  }
}
$merged = array_values($merged);

$str = "философски нагруженная";
preg_match("/.{50}$str.{50}/u", $text, $match);

preg_match_all('/\-?\d+/', $str, $matches);
$numstr = implode(' ', $matches[0]);

$arr = array_chunk(range(1, 12), 3);
foreach ($arr as $chunk) {
  echo "<div>";
  foreach ($chunk as $value) {
    echo "<div>$value</div>";
  }
  echo "</div>";
}

$digits = str_split($number);

$average = array_sum($digits) / count($digits);

preg_match('/ИНН: (\d+)/', $str, $match);
$inn = $match[1];

не могу определить откуда эти ошибки

foreach ($obj_guild['members'] as $m) {
  $username = $m['user']['username'];
  echo "$username - будет расстрелян<br>";
}

array_map(function($n) {
  return [
    'date' => $n[0],
    'sum' => $n[1]
  ];
}, array_chunk($arr, 2))