... by: Peter Karsanow, United States

Load Sudoku: ..........4.7..6...6..79..4....1.32.5..1..9.69.2....4..49..3...8...3.2..........

Weekly Extreme Jigsaw for Apr 8 to Apr 14 at sudoku.org.uk
Cyndie shape
After a lot of steps, H5 and J6 in box 8 are both 69. The solver skips over "Naked Pairs/Triples" and instead finds a Hidden Pair in column 5 that has the same effect of removing 6 from G5. Strange.
Unless I goofed up on the data entry though, your blocker isn't working on this!
Andrew Stuart writes (11-Apr-2007):
Have another go with this one, it took an hour to debug but I found the problem. It was not looking at the last two boxes for naked Pairs - which is a bit of a howler, but I am very glad you sent in the example and helped me find the problem. Doesn't effect the grade or difficulty of the puzzle since this was created and graded using my offline C++ program and the bug is purely in the javascript on the page. Nor does it speed up the solve steps a great deal for this extreme, but I'm sure it will improve a few other puzzles, so a big thanks indeed.

... by: vette_6t6_gem@msn.com, Port Charlotte, Florida

1st, your "helper" is fantastic. I type in a sudoku from the local paper, check the number of solutions to make sure there is only one, hit the step button and print out two copies of the printable version and work on it at my leisure. my only proplem is how to save and bring back the typed in version. when I save the typed in version to a file and try to open it I get the default version. What am I doing wrong?

So far as any sgestions, I wish thye curser would move to the next square each time a number is entered.

But this is a minor point. Your solver is a godsend for people like me with weak memories

Thanks

Alligator Jack -- AKA "AJ" by his great Grandchildren
Andrew Stuart writes (11-Apr-2007):
Currently there is only one save option - the save button - which saves the board (but not any notes or candidates) as a cookie - you can use re-load to get it back. If you return to the page any other way the example sudoku loads. If you want to keep many puzzles I suggest you enter them and use the email button. That gives you the important 81 number string which you can save to a text file. You can copy and paste this back into the solver using the import button

I am working on an off-line version which is much better as keeping many sudoku puzzles in a history and saving them. Hopefully ready in a month or so

... by: Paul Helbig, California, USA

What is the block you've installed on the solver. I use the solver to show the methods you use to solve a puzzle when I reach a "dead end".

The solver has helped me learn methods to solve many difficult puzzles.

Thanks,

Paul
Andrew Stuart writes (6-Apr-2007):
Paul, the blocker detects when the puzzle being solved matches either the Daily Sudoku or the Weekly Extreme Sudoku competition puzzle on the sudoku.org.uk site. The block is in effect until the competition submission deadline passes. The idea is to prevent solvers from using the solver during the competition. You will get a warning message if your puzzle is blocked, and solving stops. If you don't get a warning, the solver works normally.

... by: Greg, California

Load Sudoku: .2.3.5.4.......9...7..4..8.1.7..9..2.9..3..6.6..7..5.8.1..9..2...6.......4.8.7.5.

The above Sudoko, posted in San Jose Mercury News on 3/30/07, does not solve with your page. The program clears out the easy ones, then trys X-Wing and just shows "wait". Not sure what is going on. The CPU is not being used much, and I can exit the routine with the back button. Anyway, thought you would like to know.

Greg Buchanan
Andrew Stuart writes (6-Apr-2007):
Greg, when the solver shows "wait," it has sent the puzzle to the scanraid.com server, which executes a program written in C language to run the advanced strategies. Occasionally, internet congestion may prevent the server from getting back with a result, and the web page gets stuck with "wait." To get around the problem, always save your puzzle with the Save button. You can Save just befor the solver runs an advanced strategy. Close the solver page when the error occurs. Navigate from a fresh browser window to the solver page and then click the Re-Load button on the page. Click take step and, hopefully, you will get results this time around. Your puzzle did solve when I tried it. The solver can also appear to get stuck on "wait" if you have given it a bad puzzle. Results may be returned and shown, but the "wait" doesn't go away.

... by: Donna T, Texas

Great web site. It has helped me solve many suduko puzzles.

... by: jonnyfolk, France

Thanks for your site. I usually make my way here after staring blankly at a puzzle for 40 minutes or so. Often, I'm ashamed to say, to be told that there's something quite straightforward I'm overlooking, which is very annoying of you!

I'm using a macbookpro with core2duo and running Safari and I find the solver to work very on this set up. I thought you might like to know that...

Cheers,
Jon
Andrew Stuart writes (6-Apr-2007):
Thanks for your input, Jon!

... by: Gultekin KOMANLI, Istanbul

Great site to learn strategies for solving! Thanks a lot.

... by: Wal, Switzerland

Hallo Andrew, you saved may day - once again! Thank you very much. Brgds ... Wal

... by: lynn893, Canada

Hello! I have actually just found jigsaw sudoku puzzles and I find them absolutely fasinating!

I was working on the Daily Jigsaw sudoku competition for March 2, number 482, tough. After doing all I could by myself, I opened your solver to see if it could help me by showing me the candidates.

The next step (from where I was) showed me to place a '1' in r4c1. This does not make any sense to me at all, as there are many other 1's in row 1 and column 4. Is there any way to explain this step?

Candidates I have for 1 are:
R1 - c4, c5, c6, c9.
C4 at r1, r2, r4, r5, r6, r7, r9.

So, I don't understand how your solver came up with a 1 in R1C4.

Thanks for any light yu can shed on this for me! It really is greatly appreciated!


Andrew Stuart writes (2-Apr-2007):
Lynn, the 1 is single in the upper left hand corner box.

... by: aww, usa

Thanks, the solver is great. Very helpful and informative.

... by: Irish_guitar, Maryland USA

I find your site to be the most fabulous Sudoko site on the internet. Congratulations on a terrific site