Just feel like to visualize the graph. 
use strict;
use warnings;
use GraphViz;

my $g = GraphViz->new();
for(<DATA>){
    my @p = ($_ =~ /v\d/g);
    for(1..$#p){
        $g->add_edge($p[0] => $p[$_], color => 'grey');
    }
}
my @h = qw/v7 v8 v6 v5 v4 v3 v2 v1/;
for(1..$#h){
    $g->add_edge($h[$_-1] => $h[$_], color => 'red');
}
$g->as_jpeg("graphm.jpg");

__DATA__
v1: v2
v2: v1, v3, v4
v3: v2, v4
v4: v2, v3, v5
v5: v4, v6, v8
v6: v5, v7, v8
v7: v6, v8
v8: v5, v6, v7

[download]

In reply to Re: Finding Hamiltonian Paths using the Regexp Engine by chunlou
in thread Finding Hamiltonian Paths using the Regexp Engine by Abigail-II

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