@array = qw(1 1 1 2 3 4);

__DATA__
1 = 1 2
2 = 1 3
3 = 1 4
3 counts
$VAR1 = {
          '4' => 0,
          '1' => 0,
          '3' => 0,
          '2' => 0
        };
1 = 1 4
2 = 1 3
3 = 1 2
3 counts
$VAR1 = {
          '4' => 0,
          '1' => 0,
          '3' => 0,
          '2' => 0
        };
Unused 1: 1 2
Unused 2: 1 3
Unused 3: 1 4
next
Unused 1: 1 4
Unused 2: 1 3
Unused 3: 1 2

...
@array = qw(1 2 3 4 4 4);

__DATA__
1 = 1 2
2 = 3 4
2 counts
$VAR1 = {
          '4' => 2,
          '1' => 0,
          '3' => 0,
          '2' => 0
        };
1 = 1 4
2 = 3 4
3 = 2 4
3 counts
$VAR1 = {
          '4' => 0,
          '1' => 0,
          '3' => 0,
          '2' => 0
        };
1 = 1 2  3 4
next
Unused 1: 1 4
Unused 2: 3 4
Unused 3: 2 4