Kiddie Codes

HaB has asked for the wisdom of the Perl Monks concerning the following question:

So I have this younger cousin. He's really into fooling around with codes/ciphers and such. I was into the same stuff as a kid, so I figure I'd save him all the work of encoding and decoding by hand, and write him a coupla cool little programs that would do it for him.

So there's a code table I'd like to generate for him, but I'm not sure of the best way to store the data for easy retrieval later. The table works like this:

You take a key word, having as many non-repeating letters as possible. We'll use 'exchampion' for our example.
You write out that keyword, followed by the remaining letters in the alphabet in order, using columns of 10 letters, like so:

       -------------------
       e x c h a m p i o n
       b d f g j k l q r s
       t u v w y z . ! ? ,

       The last 4 chars are just here to complete the table.
[download]

Then, rearrange the columns in alpha order according to the topmost letter, and number them:

    1 2 3 4 5 6 7 8 9 0
    -------------------
    a c e h i m n o p x
    j f b g q k s r l d
    y w t w ! z , ? . u
[download]

Finally, number the rows from 1 to 9 vertically, 3 numbers on each row, like so:

          1 2 3 4 5 6 7 8 9 0
        |---------------------
  1,4,7 | a c e h i m n o p x
  2,5,8 | j f b g q k s r l d
  3,6,9 | y w t w ! z , ? . u
[download]

Comment on Kiddie Codes Select or Download Code

Replies are listed 'Best First'.
Script to find optimal words by tedv (Pilgrim) on Nov 10, 2000 at 00:15 UTC
Just for fun, I wrote this script to parse /usr/dict/words looking for long words without repeating letters. Here's the code: `#!/usr/bin/perl -w use strict; my @words = (); my $max_len = 0; my $delta = 2; # Number of letters less than maximum which is acceptab +le while (<>) { # Check for words which are too short my $cur_len = length; next if $cur_len + $delta < $max_len; # Check for words with repeating letters next if /(.).*\1/; # Store value in list, possibly destroying old values if ($cur_len > $max_len) { $max_len = $cur_len; @words = ($_); } else { push @words, $_; } } print @words;` [download] And if you're curious, here's the output: `ambidextrously bankruptcies bluestocking configurable considerably consumptively copyrightable customizable exclusionary flowcharting incomputable productively questionably recognizably unpredictably unprofitable upholstering` [download] A thirteen letter word might work better because you wouldn't have to pad the cypher. -Ted	[reply] [d/l] [select]
Re: Kiddie Codes by Fastolfe (Vicar) on Nov 09, 2000 at 21:21 UTC
I might do something like this: `$letter = 'a'; @ct = qw{ 11 41 71 }; $forward{$letter} = [ @ct ]; ... # Build reverse hash foreach $letter (keys %forward) { foreach $ciphertext (@{$forward{$letter}}) { $reverse{$ciphertext} = $letter; } } print join(" ", @forward{split(//, "plaintext")}); print join("", @reverse{qw{ 19 59 71 75 77 63 13 66 33 }});` [download]	[reply] [d/l]
Try a list of list refs. by TGI (Parson) on Nov 10, 2000 at 00:56 UTC
For the cyphertest lookup try using the indexes of your arrays as keys. This should be speedy and cheaper from a memory standpoint. Split your cyphertext 'letters' into two digits. Then create a list of list references.Something like this: `@ct[2,5,8]=['d', 'j', 'f', 'b', 'g', 'q', 'k', 's', 'r', 'l']; print $ct[2][3]; # Should print b.` [download] Warning:code untested as all get out.	[reply] [d/l]
Re: Kiddie Codes by HaB (Sexton) on Nov 09, 2000 at 21:19 UTC
Minor correction: In the example above, a plaintext 'b' would become ciphertext 23, 53 or 83, NOT 52. My apologies. -HaB	[reply]