Here is a page containing 4 very difficult Sudoku puzzles. I shall be printing a book of these puzzles, available in soft copy. If you like it, give your particulars here.
This post is not to discredit your good work, but I think a lot of people doesn't know that there is always a group of people specializing on ultra-ultra-ultra-hard sudoku puzzles. So when you say that some of your puzzles are suitable only for "top experts", I find it a bit funny. I found that all of your hardest puzzles so far can be solved using the Simple Sudoku Technique Set (http://www.sudopedia.org/wiki/SSTS), which to that community are considered way too simple to even mention. You might be interested to learn a subset of the solving techniques those people use at Sudopedia (http://www.sudopedia.org/wiki/Solving_Technique). Keep up the good work though. =)
Yes. These four puzzles can be solved using Simple Sudoku Technique Set (SSTS) alone.
It should be noted that some of the SSTS techniques are considered very advanced for the average person. So I do not challenge the "complex" difficulty label.
Oops I realized that I made myself sound like very expert when I am not really one. Anyway I tried the first one and it took me about 40 minutes to solve. Techniques I used are singles, box-line intersection removal, naked subsets, and XY-wing. My terminology generally follow those listed at http://www.sudopedia.org/wiki/Solving_Technique .
As for saying that the puzzles can be solved using SSTS, I simply ran the puzzles through one of the many sudoku solver programs out there. Two good programs are SudoCue (http://www.sudocue.net/download.php) and Sudoku Explainer (http://diuf.unifr.ch/people/juillera/Sudoku/Sudoku.html). And oh, I never invent the SSTS techniques so please don't call them mine. These are the techniques implemented in the Simple Sudoku solver program (http://angusj.com/sudoku/). To be frank, I am actually more interested in writing my own solver program like the above-mentioned rather than solving sudoku puzzles manually, except that the user interface of my program is quite lousy and I have not implemented as many techniques as the better ones.
Since we are at this topic, I might as well point you to the Sudoku Players' Forums (http://www.sudoku.com/boards/). This is where many of the newest and most advanced solving techniques get discovered.
By the way, I am not a maths teacher. Sorry to disappoint. =)
We can discuss how to develop the Sudoku puzzles. I will share with you about the techniques used in my computer program to solve the puzzles and, more difficult, to generate the puzzles.
Hi, We at Chessboss.com strongly believe in necessity of chess to increase both knowledge and understanding. It is unfortunate that the oldest game in the world (Chess) has a very little fan base, ChessBoss.com aims to change that. We understand the importance of blogs and the information made available on them. We are working towards building a strong fan base around our FREE chess server to better increase the use of Chess online. Your blog seems to have a large viewing public and seems to hold great information which I would love to make available to my viewing public.
I have included the code for the ChessBoss.com banner within the body of this email along with textual link information. I would be pleased to offer you the ChessBoss.com featured blogger badge to post on your site, recognizeing your blog as a leading contributor to the Chess community. Thank you for your great work and dedication, we look forward to your response!Please reply me back with subject line of your Url to avoid spam and to make sure YOU get the Award.
This post is not to discredit your good work, but I think a lot of people doesn't know that there is always a group of people specializing on ultra-ultra-ultra-hard sudoku puzzles. So when you say that some of your puzzles are suitable only for "top experts", I find it a bit funny. I found that all of your hardest puzzles so far can be solved using the Simple Sudoku Technique Set (http://www.sudopedia.org/wiki/SSTS), which to that community are considered way too simple to even mention. You might be interested to learn a subset of the solving techniques those people use at Sudopedia (http://www.sudopedia.org/wiki/Solving_Technique). Keep up the good work though. =)
ReplyDeleteHi
ReplyDeleteI remove reference to top experts. But can you try the 4 difficult puzzles and let me know if they can be solved by simple techniques.
Hi Mr. Tan
ReplyDeleteI tried the complex puzzles. They are difficult.
Yes. These four puzzles can be solved using Simple Sudoku Technique Set (SSTS) alone.
ReplyDeleteIt should be noted that some of the SSTS techniques are considered very advanced for the average person. So I do not challenge the "complex" difficulty label.
Hi
ReplyDeleteHow long did you take to solve a complex puzzle using you SSTS technique?
Were you previously a maths teacher?
Thanks Mr Tan!
ReplyDeleteI love Sudoku but could hardly time to play it cos in Singapore, everyone is busy :(
Oops I realized that I made myself sound like very expert when I am not really one. Anyway I tried the first one and it took me about 40 minutes to solve. Techniques I used are singles, box-line intersection removal, naked subsets, and XY-wing. My terminology generally follow those listed at http://www.sudopedia.org/wiki/Solving_Technique .
ReplyDeleteAs for saying that the puzzles can be solved using SSTS, I simply ran the puzzles through one of the many sudoku solver programs out there. Two good programs are SudoCue (http://www.sudocue.net/download.php) and Sudoku Explainer (http://diuf.unifr.ch/people/juillera/Sudoku/Sudoku.html). And oh, I never invent the SSTS techniques so please don't call them mine. These are the techniques implemented in the Simple Sudoku solver program (http://angusj.com/sudoku/). To be frank, I am actually more interested in writing my own solver program like the above-mentioned rather than solving sudoku puzzles manually, except that the user interface of my program is quite lousy and I have not implemented as many techniques as the better ones.
Since we are at this topic, I might as well point you to the Sudoku Players' Forums (http://www.sudoku.com/boards/). This is where many of the newest and most advanced solving techniques get discovered.
By the way, I am not a maths teacher. Sorry to disappoint. =)
Hi A Singaporean
ReplyDeleteCan you send an email to me at kinlian@gmail.com.
We can discuss how to develop the Sudoku puzzles. I will share with you about the techniques used in my computer program to solve the puzzles and, more difficult, to generate the puzzles.
Hi,
ReplyDeleteWe at Chessboss.com strongly believe in necessity of chess to increase both knowledge and understanding. It is unfortunate that the oldest game in the world (Chess) has a very little fan base, ChessBoss.com aims to change that. We understand the importance of blogs and the information made available on them. We are working towards building a strong fan base around our FREE chess server to better increase the use of Chess online. Your blog seems to have a large viewing public and seems to hold great information which I would love to make available to my viewing public.
I have included the code for the ChessBoss.com banner within the body of this email along with textual link information. I would be pleased to offer you the ChessBoss.com featured blogger badge to post on your site, recognizeing your blog as a leading contributor to the Chess community. Thank you for your great work and dedication, we look forward to your response!Please reply me back with subject line of your Url to avoid spam and to make sure YOU get the Award.
Thank you.