PHP 配列がシャッフルされるときに隣接する重複要素の生成を回避するにはどうすればよいですか?

function shuffle_array_avoid_adjacent_duplicates(array &$array) {
    $aHash = [];
    $result = [];
    foreach ($array as $key => $value) {
        $ah = md5($value);
        if (!isset($aHash[$ah])) {
            $aHash[$ah] = true;
            $result[] = $value;
        }
    }
    shuffle($result);
    return $result;
}

function shuffle_array_avoid_adjacent_duplicates(array &$array) {
    $marked = [];
    foreach ($array as $key => $value) {
        $marked[$key] = false;
    }
    while (count($marked)) {
        $key = array_rand($marked);
        $result[] = $array[$key];
        unset($marked[$key]);
        unset($array[$key]);
    }
    shuffle($result);
    return $result;
}

$array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

$shuffled_array = shuffle_array_avoid_adjacent_duplicates($array);

print_r($shuffled_array);

Array
(
    [0] => 5
    [1] => 2
    [2] => 9
    [3] => 10
    [4] => 7
    [5] => 4
    [6] => 3
    [7] => 8
    [8] => 6
    [9] => 1
)