my %h;
@h{@array_b} = @array_a;
# Now you can sort however you want, and they're linked:
for (sort {$a <=> $b} keys %h) {
  print "$_: $h{$_}\n";
}

##</code><code>##

my @sorted_values;
@sorted_values[@array_b] = @array_a; # magically sorted!

##</code><code>##

# same as above, then
@sorted_values = grep defined, @sorted_values;