use strics,
use Data::Dumper;
my @AoA = (['a','b','c'],
           ['a','b','c'],
           ['a','b','d'],
           ['a','b','d']
);
my $h,$uAoA;
map {$h->{join '-',@$_} = 1} @AoA;
push @{$uAoA},[split '_',keys %{$h}];
print Data::Dumper $uAoA;