You could simplify this code greatly by using a reverse lookup hash to find representatives' leaders:

my %old_lookup;
for my $leader (keys %old) {
   $old_lookup{$_} = $leader for @{ $old{$leader} };
}
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I don't see the need for @nobody and the oldreports() and newreports() subs. Their function seems to ensure that each value in the %old and %new hashes will be array refs. Well, they are. :) If a leader has no reps, then use an empty anonymous array reference:

   Bill => [],
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That way, the for loop that tries to iterate over the value will gracefully not.

After you build the lookup table, you can easily populate %needtomeet like so:

for my $newtl (sort keys %new) {
   my %needtomeet;
   for my $rep (@{ $new{$newtl} }) {
      my $oldtl = $old_lookup{$rep};
      push @{$needtomeet{$oldtl}},$rep if $oldtl;

      yadda yadda ...
[download]

Happy coding, and here's to keeping the PHB at bay. :)

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)