The New Sudoku Players' Forum

[RFB]

As a variation from the standard numeric puzzle has anyone produced a letter Sudoku where embedded in the puzzle is a hidden nine letter word?

Such a puzzle couldn't easily be automaticaly generated but might be a convenient competition format - just submit the hidden word rather than the complete grid.

I wonder how many 9 letter words/phrases are made of 9 different letters!

[Guest]

This is a nice idea. It would be quite easy to generate (even automatically); one should just generate any puzzle in the usual way (whatever that is!), with digits 1-9. Then choose a 9-letter word with distinct letters, and choose a row or column in the grid where you want it to appear. Then substitute the letters for the corresponding digits throughout the grid. Let's try to hide the word OBFUSCATE in column 7 of the grid on the front page of the site, and replace all 2s by O, 6s by B, 7s by F, and so on, to get

Code: Select all

963 174 258   TBS EFA OUC
178 325 649   EFC SOU BAT
254 689 731   OUA BCT FSE

821 437 596   COE ASF UTB
496 852 317   ATB CUO SEF
735 961 824   FSU TBE COA

589 713 462   UCT FES ABO
317 246 985   SEF OAB TCU
642 598 173   BAO UTC EFS

You can do the same for the puzzle as well. For what it is worth, of the 16692 9-letter words in a word list I have, 1820 have 9 different letters. Obviously different word lists will give different answers!

[Animator]

A nice idea, but it would be hard to do that on a 9x9 puzzle... as in, having a word means that very puzzles uses a different number/letter type... as in, now it is simply, a 9x9 has the digits 1 to 9, but to play with letters on a 9x9 one you have a problem (it varies everytime)... Perhaps a 25x25 puzzle would be easier for that (although then one letter has to be dropped)? :)

Also, why would it have to be a 9 letter word and/or have 9 different letters?

Here is an example of a 5 letter word, with only 4 different letter (only relevant cells are filled in):

* * * | * H * | * * *
* * * | * * E | * * *
* * * | * * * | L * *
-----------------------
* * * | * * * | * L *
* * * | * * * | * * O
* * * | * * * | * * *
-----------------------
* * * | * * * | * * *
* * * | * * * | * * *
* * * | * * * | * * *

[Guest]

I agree it's quite a nice idea, but I think there are a couple of problems...

You would need to be careful that the last cell completed is one of the letters in the word, otherwise the puzzler could get the answer before completing the puzzle. This obviously makes setting the puzzle a lot harder - In fact, I'm fairly sure it's not even possible.

Equally it becomes a game of hangman - how many 9 letter words would you not guess with only one or two letters missing?

Perhaps you could have two words - leave the puzzle numeric, and give one word as a key (saying which row, col or block it's in). This would define a code (e.g. a=1, f=2, etc.). The puzzler then needs to find the other word elsewhere in the puzzle using the same code. That way the puzzle setter only has to ensure the last unit completed (rather than the last cell), which is probably a lot easier. The two words need to be anagrams of course, which limits the possibilities.

[RFB]

I agree it's quite a nice idea, but I think there are a couple of problems...

You would need to be careful that the last cell completed is one of the letters in the word, otherwise the puzzler could get the answer before completing the puzzle. This obviously makes setting the puzzle a lot harder - In fact, I'm fairly sure it's not even possible.

Equally it becomes a game of hangman - how many 9 letter words would you not guess with only one or two letters missing?

I don't think it is particularly important that someone could find the word before completing the entire puzzle or that you could guess a few missing letters.

Today when when you enter any sort of newspaper competition you are essentially entering a lucky dip - the difficulty of the puzzle only slightly modifies the size of the post bag for choosing the winner.

Most of us do Sudoku and crosswords for the intellectual exercise rather than competition entry so would carry on to solve the entire puzzle even if we had spotted the hidden word.

In AFJ's excellent sample I was suprised how well Obfuscate was obfuscated! Even knowing what the word is and where it is it is not readily obvious (to me).

I suggested a nine letter word because it fits with the standard 9x9 grid but obviously the same idea works with larger grids, shorter words, or phrases.

[EdwardP]

Is it possible to use any 9-letter word for a word sudoku amd simply distinguish the letters by underscoring e.g. a repeated E or O. It might make the puzzle more interesting.

It won't always be easy to spot the word by the repetition and using short phrases would further complicate the puzzle

What do people think?

[RW]

I've seen a book with "Wordokus"- letter sudokus where a word was to be formed on the diagonal. But the words did not need to contain all 9 letters, some letters could also appear several times in the word. The puzzles in that book wasn't really any more interesting than normal sudokus, as it was possible to solve them without considering the words. To make it interesting, the puzzle in itself should have multiple solutions, but only one that produces a valid word. Fragment from such a puzzle could be:

Code: Select all

K es Y | B eo A | R D os
  es   |   eo   |     os


Without the word constraint there would be two solutions, but as there has to be a word in the row we can tell that the only solution is "keyboards" ("ksybeardo" is not a word in any language I know of anyway ).

Of course the deadly patterns should be larger than in my example to make it really interesting.

RW

[TN_Mike]

I remember discussing this a while back with tso, we came up with something that requires the word to complete the puzzle. See sudoku.top-notch.co.uk/superwordoku.asp { page no longer exists } for some examples (these actually embed two words.)

Also noteworthy is Steve Schaefer's "code-doku" which embeds an entire sentence. See www.mathrec.org/sudoku/codedoku.html