gistfile1.txt

sub next-happy($n) { [+] $n.comb.map(* ** 2) }

sub no-loop-found(@n) {
    my $seen = SetHash.new;
    for @n -> $n {
        return False if $seen{$n};
        $seen{$n} = True;
    }
    return True;
}

sub is-happy($n) {
    no-loop-found($n, &next-happy ... 1);
}

say (1..100).grep({ is-happy($_) });