view release on metacpan or  search on metacpan

lib/Algorithm/X/DLX.pm  view on Meta::CPAN

=head1 SYNOPSIS

  use Algorithm::X::DLX;

  my $problem = Algorithm::X::ExactCoverProblem->new($width, \@input_rows, $secondary_column_count);

  my $dlx = Algorithm::X::DLX->new($problem);

  my $result = $dlx->search();
  foreach my $row_indices (@{$result->{solutions}}) {
    ...

  Or better, especially with searches taking a very long time

  my $iterator = $dlx->get_solver();
  while (my $row_indices = &$iterator()) {
    ...
  

=head1 The Example applications provided under examples/...

There are scripts and modules for various exact cover problems: 

N-queens, Langford, Sudoku, N-pieces and Pentominoes

See L<Algorithm::X::Examples>.

=head2 L<examplesE<sol>dlx.pl|https://metacpan.org/dist/Algorithm-X-DLX/source/examples/dlx.pl>

And a more generic script that makes use of this lib.

  examples$ ./dlx.pl -pv < data/knuth_example.txt
  1 0 0 1 0 0 0
  0 0 1 0 1 1 0
  0 1 0 0 0 0 1

  solutions: 1

=head1 DEPENDENCIES

=over 5

=item * L<Carp>

=back

=head1 COPYRIGHT AND LICENSE

The following copyright notice applies to all the files provided in
this distribution, unless explicitly noted otherwise.

This software is copyright (c) 2025 by Steffen Heinrich

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

=head1 SEE ALSO

Donald E. Knuth, Stanford University 2000 L<Dancing Links|http://arxiv.org/pdf/cs/0011047v1> 

L<Introduction to Exact Cover Problem and Algorithm X|https://www.geeksforgeeks.org/introduction-to-exact-cover-problem-and-algorithm-x/>

Peter Pfeiffer BSc, Linz 2023 L<Uncovering Exact Cover Encodings|https://epub.jku.at/obvulihs/download/pdf/9260418>

=cut