#!/usr/bin/perl
use strict;

# Calculate some "masks" outside the loops
my (%nummasks,%wordmasks);
map{my $k=.5*$_*($_+1); $nummasks{$k}=wordmask($k)}1..446; # ok, this line was tweaked from another poster
map{$wordmasks{$_}=wordmask($_)}('ONE','THREE','SIX','TEN');

# Loop through the THREE candidates
for my $three (keys %nummasks) {
  next unless $nummasks{$three} eq $wordmasks{'THREE'};
  my @three = split(//,$three);

  # Loop through the TEN candidates
  for my $ten (keys %nummasks) {
    next unless $nummasks{$ten} eq $wordmasks{'TEN'};
    my @ten = split(//,$ten);
    next unless $ten[0] == $three[0] && $ten[1] == $three[3];
    my %used = map{$_,1} (@three);
    next if $used{$ten[2]};
 
    # Loop through the ONE candidates
    for my $one (keys %nummasks) {
      next unless $nummasks{$one} eq $wordmasks{'ONE'};
      my @one = split(//,$one);
      next unless $one[1] == $ten[2] && $one[2] == $ten[1];
      my %used = map{$_,1} (@three,@ten);
      next if $used{$one[0]};

      # Find a SIX and we've solved it
      for my $six (keys %nummasks) {
        next unless $nummasks{$six} eq $wordmasks{'SIX'};
        my @six = split(//,$six);
        my %used = map{$_,1} (@three,@ten,@one);
        next if $used{$six[0]} || $used{$six[1]} || $used{$six[2]};
        print "ONE:\t$one\nTHREE:\t$three\nSIX:\t$six\nTEN:\t$ten\n";
      }
    }
  }
}


sub wordmask { # generate a "pattern mask", 56675 => abbca
  my $mask = shift;
  my $letter = 'a';
  while ($mask =~ /([^a-z])/) {
    $mask =~ s/$1/$letter/g;
    $letter++;
  }
  return $mask;
}