#!/usr/bin/perl
use warnings;
use strict;
use Benchmark qw/cmpthese/;

my %graph =(
          'F' => ['B','C','E'],
          'A' => ['B','C'],
          'D' => ['B'],
          'C' => ['A','E','F'],
          'E' => ['C','F'],
          'B' => ['A','E','F'],

           x => ['y','z'],
           y => ['u','v'],
           z => ['w','x'],
           u => [],
           v => [],
           w => [],
        );

sub try_path_depth {
  my ($start,$end,@sofar) = @_;
  if ($start eq $end) {
     return 1;
  }
  push @sofar,$start;

  foreach my $node(@{ $graph{$start} }){
     unless (grep $_ eq $node,@sofar){
      if(try_path_depth($node,$end,@sofar)){
        print "@sofar $end\n";
      }
    }
   }
} # try_path_depth

sub path_depth {
  my ($start,$end) = @_;
  print "$start => $end\n";
  try_path_depth($start,$end);
} # path_depth

sub uniq {
  my %uniq;
  @uniq{@_} = ();
  return keys %uniq;
} #uniq

sub try_path_breadth {
  my($start,$end) = @_;
  my @from = ($start);
  my %path = ($start => [$start]);
  my $change = 1;
  while($change){
    undef $change;
    my %newpath;

    my @to = uniq(map @{ $graph{$_} },@from);
    foreach my $from (@from) {
      foreach my $to (@{ $graph{$from} }){
        for my $path (grep { $_ !~ /$to/ and $change = 1} @{$path{$fro
+m}}){
          unless(grep $path.$to eq $_,@{$newpath{$to}}){
            push @{ $newpath{$to} },$path.$to;
            $change = 1;
          }
        }
      }
    }
    %path = %newpath;
    print "$_\n" foreach @{ $path{$end} };
    @from = @to;
  }
} # try_path_breadth

sub path_breadth {
  my ($start,$end) = @_;
  print "$start => $end\n";
  try_path_breadth($start,$end);
} # path_breadth


sub find_paths {
...
}

sub find_paths_sc {
...
}

sub node_to_int {
...
}

sub update_completed_paths {
...
}

sub path_completed {
...
}


cmpthese(0,{depth => sub{
              path_depth 'B','E';
              path_depth 'B','D';
              path_depth 'z','v';},
            breadth => sub{
              path_breadth 'B','E';
              path_breadth 'B','D';
              path_breadth 'z','v';},
            limbic => sub{
              print @{find_paths 'B','E',\%graph},
                @{find_paths 'B','D',\%graph},
                @{find_paths 'z','v',\%graph};},
            limbic_sc => sub{
              print @{find_paths_sc 'B','E',\%graph},
                @{find_paths_sc 'B','D',\%graph},
                @{find_paths_sc 'z','v',\%graph};},
           });
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