# Feedback and Questions

I've received a lot of interesting comments and questions from Sudoku fans over the last few years and this page
is where I try to answer them. Please feel free to drop me a note on the side of the page or try the Facebook
comment box. Or you can email me directly at andrew@str8ts.com.
**Post a Comment or Question here...**

## Tuesday 17-Mar-2009

## ... by: patriotkiller18, usa

## Monday 16-Mar-2009

## ... by: Felix, California

http://www.scanraid.com/Escargot

## Thursday 12-Mar-2009

## ... by: Oliver B., Germany

Load Sudoku: CLICK TO LOADI found this Sudoku X in a German magazine called "Sudoku Logisch Spezial" (Issue No. 14 from June 2008).

Some cells of the grid are restricted to even numbers. These are C7, C8, D3, E5, F2, G1, I2 and I7.

The difficulty is rated "easy"... *sigh*

After spending some hours I gave up, tried again some weeks later and so on - until today.

I remembered your web-site and wanted to be shown what I have overlooked and I the end it claimed "Run out of known strategies."

For you are interested in examples that can't be solved on this page I sent this to you. The SolutionCount-Button did not work! ("Not available just yet")

I don't know whether there is a solution derived from any strategies, maybe it is only a misprint, but the given one on the last pages of the magazine is this:

258634791

794512386

163789245

936145827

572863914

481927563

617258439

849376152

325491678

Apart from that I just can say that this homepage is a great benefit when stuck in a puzzle.

Thanks a lot.

Thanks for your example. It is a flawed Sudoku X (or I hope you didn't miss a clue or transpose a number). If what you have given me is correct then the publisher has gone a bad job of checking their puzzles. I find 34 solutions for this puzzle, which is why it can't be solved logically.

(If anyone loads this, change the URL to be sudokuX.htm - it loads in the normal sudoku solver)

## Sunday 8-Mar-2009

## ... by: François, France

## Sunday 8-Mar-2009

## ... by: Doug M, SE PA

## Friday 20-Feb-2009

## ... by: Martin, France

## Sunday 15-Feb-2009

## ... by: Carl, USA - California

I'd like to put in a plug for a feature. I tried using the save and restore feature on your regular solver page "http://www.scanraid.com/sudoku.htm", and the results were nearly what I had expected. Any solved squares in the saved cookie were restored.

My request is to make this feature much much more useful. I actually use your solver as an aid (an online blackboard mostly) to hold the candidates for each cell, as I work on solving "Killer Sudoku" puzzles. I click on each cell of a cage and enter the possible candidates as restricted by the cage values. What I would like your SAVE function to do, is to save all the candidates from the screen to the cookie, and restore all the selected candidates when RE-LOAD is selected. If a sell is "solved", it will only have one candidate, if it is unsolved, it will contain 2 or more candidates. This could be accomplished by using a comma or semicolon separated list instead of just a list of 81 digits/characters. Since my reason for asking is so that I can save the state when I'm working a puzzle, or stuck and want to return later, the major work in getting back t where I was is resetting the candidates. The current RE-LOAD function is useful, but f makes me re-eliminate all the candidates that I've already eliminated in prior work.

Thanks.

-Carl

## Wednesday 11-Feb-2009

## ... by: Peter B, Los Angeles, CA (ex-pat Brit originally from Oxford, UK)

So I turned to Google and after looking at a few sites I came across yours - and a welcome breath of fresh air :)

Congratulations on the work you've done - this is an excellent tool for newcomers and old hands alike IMHO. I know my skills have certainly benefited greatly from it. More power to your elbow!

## Tuesday 10-Feb-2009

## ... by: Dennis, USA

However, you should look at Sudoku X where this feature is done by design. I have a solver and some additional strategies for this puzzle, which is quite fun

## Saturday 31-Jan-2009

## ... by: rodnishi, hawaii

i have a question and i don't see it in the strategy explanation. how does the hidden unique rectangle work? when i was rying to solve a puzzle, one of the steps involved the hidden unique rectangle.

mahalo,

rod

I have decided to split out 'Hidden Unique Rectangles' from the 'Unique Rectangles' strategy as I've had many emails about this. There is a strategy page for it here

/Hidden_Unique_Rectangles

- but it was not obvious how to find that page. Hopefully this will make it clearer.

All the best with your solving

## Friday 30-Jan-2009

## ... by: Ygor, Netherands

This is a great site! I am wondering what the score is of the most difficult sukoku that your solve can solve? And do you have this sudoku as an example?

Cheers,

Ygor

THIS ONE

which I score as 2528 but this won't show up on the web site grader as I exclude Nishio/Bowmans, but you are welcome to discover a better solve solution that doesn't involve them - I'd be very interested to see one.