Advent of code 2022/25

Ajax Direct

function SNAFU($number)
{
    $nums  = "=-012";
    return $number->chars->reverse()->reduce(fn ($sum, $char, $i) =>
        $sum + (strpos( $nums, $char) - 2) * pow(5, $i)
    , 0, true);
}

function UFANS($number)
{
    $nums  = "=-012";
    $chars = scalar(base_convert($number, 10, 5))->chars();

    // Offset 3 & 4 to 1= & 1-
    while ($chars->hasValue(3) || $chars->hasValue(4)) {
        foreach ($chars as $i=>$char) {
            if ($char == 3) {
                $chars[$i - 1] = ($chars[$i - 1] ?? 0) + 1;
                $chars[$i] = -2;
            }

            if ($char == 4) {
                $chars[$i - 1] = ($chars[$i - 1] ?? 0) +  1;
                $chars[$i] = -1;
            }
        }
    }

    return $chars->mapAssoc(function ($i, $a) use ($chars, $nums) {
        return [($i + $chars->count()) => $nums[$a + 2]];
    })->sortKeys()->values()->join("");
}

$solution_1 = UFANS($input->lines->map("SNAFU")->sum());
$solution_2 = "⭐";