111011001010011110100010100001
111010000010010110000010000001
000101011100001000110101110000
000101111101001001111101111110
111011001010111110100010100001
000100010100000000010001010000

##</code><code>##

my @strings = qw/111011001010011110100010100001
  111010000010010110000010000001
  000101011100001000110101110000
  000101111101001001111101111110
  111011001010111110100010100001
  000100010100000000010001010000/;

foreach my $string (@strings) {
    my @items = split //, $string;
    $string = \@items;
}

for ( my $i = 0 ; $i < @strings ; $i++ ) {
    for ( my $j = $i + 1 ; $j < @strings ; $j++ ) {
        my ( $c00, $c01, $c10, $c11 ) = ( 0, 0, 0, 0 );
        for ( my $k = 0 ; $k < @{ $strings[$i] } ; $k++ ) {
            $c00++
              if ${$strings[$i]}[$k] == 0 && ${$strings[$j]}[$k] == 0;
            $c01++
              if ${$strings[$i]}[$k] == 0 && ${$strings[$j]}[$k] == 1;
            $c10++
              if ${$strings[$i]}[$k] == 1 && ${$strings[$j]}[$k] == 0;
            $c11++
              if ${$strings[$i]}[$k] == 1 && ${$strings[$j]}[$k] == 1;
        }
        print join( "\t", $i, $j, $c00, $c01, $c10, $c11 ), "\n";
    }
}