my @TwoD = ( ['A','B','C'], ['A','D','C'], ['A','B','C'] );
my ( $slotH, %slotH ) = (-1,());
my @result = ();
for ( my $i1 = 0; $i1 <= $#TwoD; $i1++ ) {
    for ( my $i2 = 0; $i2 <= $#{ $TwoD[ $i1 ]}; $i2++ ) {
        my $v = $TwoD[ $i1 ][ $i2 ];
        defined( $slotH{ $v } ) or $slotH{ $v } = ++$slotH;
        $result[$i1][$slotH{ $v }] = $v;
    }
    for ( my $i2 = 0; $i2 <= $slotH; $i2++ ) {
        $i2 and print "\t";
        print ( $result[$i1][$i2] || '' );
    }
    print "\n";
}

##</code><code>##

A       B       C
A               C       D
A       B       C