#!/usr/bin/perl
use strict;
use warnings;
$|++;

# is using Algorithm::FastPermute cheating? i hope not.
use Algorithm::FastPermute qw/ permute /;
## use Data::Dumper;                      # see what's inside...


( @ARGV == 2 and $ARGV[0] < $ARGV[1] ) # process arguments
  ? my( $lower, $upper ) = @ARGV
  : die 'usage: ' . $0 . ' lower upper' . $/;

NUMBER: for my $try ( $lower..$upper )
{ # try each number within bounds
  my @digits = split //, '*' . $try;   # makes ( '*', 1, 2, 3, etc )
  my @permutations;                    # holds permutations

  # push permutations onto array
  #   unless the permutation has a '*' on either end
  permute {
    push @permutations, [ @digits ] 
      unless @digits->[-1] eq '*' or @digits->[0] eq '*';
  } @digits;

## # uncomment to see what's inside...
##   print Dumper \@permutations;

  my %results =                        # product => operation pairs
    map { eval( $_ ) || 0, $_ }        #     create pair
    map { join( '', @{ $_ } ) }        #   stringify the array
    @permutations;                     # for each permutation

## # uncomment to see what's inside...
##   print Dumper \@permutations;

  defined $results{ $try }             # if i found one
    && print( $try,                    # print it
      ' is vampire (',
      $results{ $try },                # and how i got there
      ')', $/ )
    && next NUMBER;
}
##</code><code>##

.