use Data::Dumper;
use strict;

sub count_unique {
	print Dumper \@_;
	my %uniq;
	$uniq{0+\$_}++ foreach @_;
	return sprintf (
        "CTU: %d unique entities (%d duplicates):\n",
        scalar keys %uniq,
        scalar ( grep { $uniq{$_} > 1 } keys %uniq ),
    );
}

sub find_unique_items_in {
    my $set = shift;
	print Dumper $set;

    my (%uniq, @out) = ();

    for my $i (@$set) {
        $uniq{ $i }++;
    }

    return sprintf (
        "FUI: %d unique entities (%d duplicates):\n",
        scalar keys %uniq,
        scalar ( grep { $uniq{$_} > 1 } keys %uniq ),
    );
}


my ($x,$y,$z)=qw(a b c);
print count_unique($x,$y,$z),$/;
print find_unique_items_in([\$x,\$y,\$z]),$/;

print count_unique($x,$y,$y),$/;
print find_unique_items_in([\$x,\$y,\$y]),$/;

print count_unique($x,$x,$y,$y),$/;
print find_unique_items_in([\$x,\$x,\$y,\$y]),$/;

print count_unique($z,$z,$z,$z),$/;
print find_unique_items_in([\$z,\$z,\$z,\$z]),$/;

print count_unique($x,$x,$y,$y,$z,$z),$/;
print find_unique_items_in([\$x,\$x,\$y,\$y,\$z,\$z]),$/;
__END__
$VAR1 = [
          'a',
          'b',
          'c'
        ];
CTU: 3 unique entities (0 duplicates):

$VAR1 = [
          \'a',
          \'b',
          \'c'
        ];
FUI: 3 unique entities (0 duplicates):

$VAR1 = [
          'a',
          'b',
          ${\$VAR1->[1]}
        ];
CTU: 2 unique entities (1 duplicates):

$VAR1 = [
          \'a',
          \'b',
          $VAR1->[1]
        ];
FUI: 2 unique entities (1 duplicates):

$VAR1 = [
          'a',
          ${\$VAR1->[0]},
          'b',
          ${\$VAR1->[2]}
        ];
CTU: 2 unique entities (2 duplicates):

$VAR1 = [
          \'a',
          $VAR1->[0],
          \'b',
          $VAR1->[2]
        ];
FUI: 2 unique entities (2 duplicates):

$VAR1 = [
          'c',
          ${\$VAR1->[0]},
          ${\$VAR1->[0]},
          ${\$VAR1->[0]}
        ];
CTU: 1 unique entities (1 duplicates):

$VAR1 = [
          \'c',
          $VAR1->[0],
          $VAR1->[0],
          $VAR1->[0]
        ];
FUI: 1 unique entities (1 duplicates):

$VAR1 = [
          'a',
          ${\$VAR1->[0]},
          'b',
          ${\$VAR1->[2]},
          'c',
          ${\$VAR1->[4]}
        ];
CTU: 3 unique entities (3 duplicates):

$VAR1 = [
          \'a',
          $VAR1->[0],
          \'b',
          $VAR1->[2],
          \'c',
          $VAR1->[4]
        ];
FUI: 3 unique entities (3 duplicates):