The boy learned about variables the other day and thought it was cool how letters could stand for numbers. I was reminded of the word math puzzles I had seen where you have to figure out what digit each letter represents to make a valid math problem, like:

     one
+   four
========
    five
[download]

    spec
+   perl
========
    opus
[download]

And so became the word math program. It's just a brute force thing, but kinda cool.

Yuck+Foo

#!/usr/bin/perl

  use strict;
  use Data::Dumper;

  my $DictFile = '/usr/share/dict/words';
  my $MinLen   =  3;
  my $MaxLen   =  6;
  my $Todo     = 10;
  my $Hint     =  1;

  my $dict = read_dict($DictFile, $MinLen, $MaxLen);

  #my $dict = read_data($MinLen, $MaxLen);

  my $pre_selects = (@ARGV) ? [@ARGV] : [];

  while ($Todo) {

    my $words = choose_words($dict, $pre_selects);
    my $numbs = encode_words($words);

    if ($numbs) {
      ($words, $numbs) = sort_lists($words, $numbs);

      if ($numbs->[0] + $numbs->[1] == $numbs->[2]) {
        $Todo--;
        show_it($MaxLen, $words, $numbs, $Hint);
      }
    }
  }

#-----------------------------------------------------------
sub show_it {

  my $len   = shift;
  my $words = shift;
  my $numbs = shift;
  my $hint  = shift;

  $hint = ($hint) ? make_hint($words, $numbs) : '';

  printf "  %*s\n", $len, $words->[0];

  for my $i (1..@$words-2) {
    printf "+ %*s\n", $len, $words->[$i];
  }

  printf "==%s\n", '=' x $len;
  printf "  %*s  $hint\n\n", $len, $words->[-1];
}

#-----------------------------------------------------------
sub make_hint {

  my $words = shift;
  my $numbs = shift;

  my $w_str = join('', @$words);
  my $n_str = join('', @$numbs);

  my $r = rand(length($w_str));
  my $w = substr($w_str, $r, 1);
  my $n = substr($n_str, $r, 1);

  return "($w = $n)";
}

#-----------------------------------------------------------
sub sort_lists {

  my $words = shift;
  my $numbs = shift;

  my @list;

  for my $i (0..@$numbs - 1) {
    push @list, {
      i    => $i,
      numb => $numbs->[$i],
    };
  }

  @list = sort { $a->{numb} <=> $b->{numb} } @list;

  my (@new_words, @new_numbs);

  while (my $i = shift(@list)) {
    push @new_words, $words->[$i->{i}];
    push @new_numbs, $numbs->[$i->{i}];
  }

  return (\@new_words, \@new_numbs);
}

#-----------------------------------------------------------
sub encode_words {

  my $words = shift;

  my %letters;
  my @numbs;

  for my $word (@$words) {
    for my $char (split('', $word)) {
      $letters{$char}++;
    }
  }

  my @letters = keys(%letters);
  (@letters > 9) and return;

  my @digits = (0..9);

  my %xlate = {};

  while (my $letter = splice(@letters, rand(@letters), 1)) {
    $xlate{$letter} = splice(@digits, rand(@digits), 1);
  }

  for my $word (@$words) {
    my $numb;
    for my $char (split('', $word)) {
      $numb .= $xlate{$char};
    }
    push @numbs, $numb;
  }

  return \@numbs;
}

#-----------------------------------------------------------
sub choose_words {

  my $dict  = shift;
  my $words = shift;

  my @list = @$words;

  while (@list < 3) {
    push @list, $dict->[rand(@$dict)];
  }

  return \@list;
}

#-----------------------------------------------------------
sub read_dict {

  my $file = shift;
  my $min  = shift;
  my $max  = shift;

  my @words;

  open (my $fh, '<', $file) or die;

  while (my $line = <$fh>) {
    chomp $line;
    (length($line) < $min) and next;
    (length($line) > $max) and next;
    ($line =~ tr/A-Z/A-Z/) and next;

    push @words, $line;
  }

  return \@words;
}

#-----------------------------------------------------------
sub read_data {

  my $min  = shift;
  my $max  = shift;

  my @words;

  while (my $line = <DATA>) {
    chomp $line;
    (length($line) < $min) and next;
    (length($line) > $max) and next;
    ($line =~ tr/A-Z/A-Z/) and next;

    push @words, $line;
  }

  return \@words;
}

__DATA__
zero
one
two
three
four
five
six
seven
eight
nine
ten
eleven
twelve
thirteen
fourteen
fifteen
sixteen
seventeen
eighteen
nineteen
twenty
[download]

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