# don't run this code on every match: the idea is the qr// needs
# to be computed only once.
my $valid    = join "|", map { quotemeta } @valid;
my $valid_re = qr/^$valid$/;

# now match as many times as you like.
print "$_: " . (/$valid_re/ ? "okay" : "not okay") . "\n"
        for @a_bunch_of_inputs;