use strict;
use warnings;

use Graph::Simple;
use Data::Dumper;

my $g = Graph::Simple->new ( is_directed => 0, is_weighted => 1);

$g->add_edge( 'A',  'B', 200 );
$g->add_edge( 'A',  'C', 700 );
$g->add_edge( 'A',  'D', 700 );

$g->add_edge( 'B',  'C', 500 );
$g->add_edge( 'B',  'D', 500 );

$g->add_edge( 'C',  'D', 600 );

my @path = $g->shortest_path('A', 'D');

print Dumper (\@path);

##</code><code>##

$VAR1 = [
          'A',
          'B',
          'D'
        ];