#!usr/bin/perl -w
use strict;

my %HOA;
my %seen;

while (<DATA>)
{
  my($name1,$name2,$value) = split;
  push ( @{$HOA{$name1}}, $value) unless $seen{$value}++;
  push ( @{$HOA{$name2}}, $value) unless $seen{$value}++;
}

foreach my $name (sort keys %HOA)
{
  print "$name - ", "@{$HOA{$name}}","\n";
}

=Program Prints:
aaa - 123 234 345
bbb - 456 567
ccc - 678
=cut
 

__DATA__
aaa bbb 123
aaa ccc 234
aaa ddd 345
bbb ccc 456
bbb ddd 567
ccc ddd 678