61 #2
123456789101112
multi ips($num, 0) { $num < 255 ?? [ $num.Int.Str ] !! [,] }
multi ips($num, $l = 3) {
gather for 1 .. 3 -> UInt $s {
my $n = $num.substr: 0, $s;
if $n <= 255 && $l <= $num.chars - $s <= $l * 3 {
take "{ $n.Int }.$_" for ips $num.substr($s), $l - 1
}
}.unique
}
say ips "25525511135"
Raku
INFO