use strict;
use warnings;

use 5.022;

use Graph::Easy;
say qq{Using Graph::Easy version $Graph::Easy::VERSION};

my @events = (
   [ 1, 2, 5, 6, 7, 8, 9, 11 ],
   [ 1, 2, 5, 6, 7, 8, 10, 11 ],
   [ 1, 4, 5, 6, 7, 8, 9, 11 ],
   [ 1, 4, 5, 6, 7, 8, 10, 11 ],
   [ 1, 3, 5, 6, 7, 8, 9, 11 ],
   [ 1, 3, 5, 6, 7, 8, 10, 11 ],
   [ 1, 7, 8, 10, 11 ],
   );

my %edges;
foreach my $event ( @events )
{
    foreach my $idx ( 1 .. $#{ $event } )
    {
        $edges{ join q{ -> }, $event->[ $idx - 1 ], $event->[ $idx ] } ++;
    }
}

say for
   map { unpack q{x8a*} }
   sort
   map { pack q{NNa*}, split( m{ -> } ), $_ }
   keys %edges;

my $graph = Graph::Easy->new();
$graph->add_edge( split m{ -> } ) for keys %edges;

print $graph->as_ascii();