use strict;
use warnings;
use Data::Dump qw/pp dd/;


# https://perlmonks.org/?node_id=11141490

my $n=8;

die "n must not be odd" if $n%2;


my @nodes = 0 .. $n-1;

my $center = shift @nodes;


sub rotate(\@) {
    my $r = shift @{$_[0]};
    push @{$_[0]},$r
}

sub get_edges {
    my @verts = @_;
    my $left  = $#verts/2;
    my @res = map [ $verts[$_-1], $verts[-$_] ], 1..$left;
    return [@res,[$center,$verts[$left]]];
}

sub get_matrix{
    my (@colored) = @_;
    my @inc_matrix;
    while ( my ($color,$color_set) = each @colored ) {
        for my $edge (@$color_set) {
            my ($v0,$v1) = @$edge;
            $inc_matrix[ $v0 ][ $v1 ] = $color;
            $inc_matrix[ $v1 ][ $v0 ] = $color;
        }
    }
    return \@inc_matrix;
}

my @colored;
for(@nodes){
    #pp \@nodes;
    push @colored, get_edges(@nodes);
    rotate(@nodes);
}

pp \@colored;


pp get_matrix(@colored);