/ 
Algorithm-Graphs-TransitiveClosure-Tiny-0.01
River stage zero No dependents
/ Algorithm::Graphs::TransitiveClosure::Tiny

NAME

Algorithm::Graphs::TransitiveClosure::Tiny - Calculate the transitive closure.

SYNOPSIS

use Algorithm::Graphs::TransitiveClosure::Tiny qw(floyd_warshall);

my $graph = {
             0 => {0 => undef},
             1 => {1 => undef, 2 => undef, 3 => undef},
             2 => {1 => undef, 2 => undef},
             3 => {0 => undef, 2 => undef, 3 => undef},
            };

floyd_warshall $graph;

print "There is a path from 2 to 0.\n" if
    exists($graph->{2}) && exists($graph->{2}->{0});

The latter can also be written shorter provided you accept autovivification:

print "There is a path from 2 to 0.\n" if exists($graph->{2}->{0});

DESCRIPTION

This is taken from Algorithm::Graphs::TransitiveClosure. The difference is that this implementation of floyd_warshall():

  • works on hashes only,

  • uses undef as hash value, so an incidence must be checked with exists(),

  • assumes that the hash keys are integers 1, ..., N (for some integer N) and this N must be passed as second argument. This is needed to fix a problem in the original implementation.

For further information refer to Algorithm::Graphs::TransitiveClosure.

AUTHOR

Abdul al Hazred, <451 at gmx.eu>

BUGS

Please report any bugs or feature requests to bug-algorithm-graphs-transitiveclosure-tiny at rt.cpan.org, or through the web interface at https://rt.cpan.org/NoAuth/ReportBug.html?Queue=Algorithm-Graphs-TransitiveClosure-Tiny. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SEE ALSO

Algorithm::Graphs::TransitiveClosure, Text::Table::Read::RelationOn::Tiny

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc Algorithm::Graphs::TransitiveClosure::Tiny

You can also look for information at:

LICENSE AND COPYRIGHT

This software is copyright (c) 2022 by Abdul al Hazred.

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