# Use an HoH instead of simple array
my %categories;
foreach (@sub) {
   $categories{length($_)}{$_} = undef;
}

# ... when you need it...
sub matches_any {
   my $t = shift;
   foreach my $len (keys %categories) { # We could also sort here...
      return 1 if exists $categories{$len}{substr($t, 0, $len)};
   }
   return 0;
}