| View previous topic :: View next topic |
| Author |
Message |
oaxen
Joined: 10 Jul 2006
Posts: 96
|
 Posted: Fri May 15, 2009 7:33 am Post subject: Basics |
 |
|
Thank you very much Danny for your interesting puzzles. I start every day with one of them.
A question: have you never thought about to deliver them with all the basics solved? Most ideal would be if it is so and when printing the pencil marks also can appear on the paper. ( I hate to sit before the computer solving the puzzles) Then all the dull work is done and one can start with the real thing. 
Kind regards
Lars |
|
| Back to top |
|
 |
keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
|
| Posted: Fri May 15, 2009 12:01 pm Post subject: |
|
|
Lars,
Get yourself a copy of Sudoku Susser. You can turn off all the advanced solving techniques, leaving only the ones you consider basic.
Then, copy & paste the puzzle into the Susser, hit Shift+D to solve, and print. It will take no more than ten seconds.
Keith |
|
| Back to top |
|
|
daj95376
Joined: 23 Aug 2008
Posts: 3854
|
| Posted: Fri May 15, 2009 2:57 pm Post subject: Re: Basics |
|
|
| oaxen wrote: | Thank you very much Danny for your interesting puzzles. I start every day with one of them.
A question: have you never thought about to deliver them with all the basics solved? Most ideal would be if it is so and when printing the pencil marks also can appear on the paper. ( I hate to sit before the computer solving the puzzles) Then all the dull work is done and one can start with the real thing.
Kind regards
Lars |
Hello Lars. I'm glad that you enjoy my puzzles!
My puzzle generator isn't very sophisticated, and tends to have a large number of Singles near the beginning. I was afraid that others would feel as you do about resolving so many initial Singles.
Awhile back, I posted a puzzle with the Singles solved and asked for input. The response was all negative. So, I dropped the idea.
Regards, Danny A. Jones |
|
| Back to top |
|
|
oaxen
Joined: 10 Jul 2006
Posts: 96
|
| Posted: Fri May 15, 2009 3:34 pm Post subject: |
|
|
Hello Lars. I'm glad that you enjoy my puzzles!
My puzzle generator isn't very sophisticated, and tends to have a large number of Singles near the beginning. I was afraid that others would feel as you do about resolving so many initial Singles.
Negative or ignorant
May be that especial day not so many was awake? |
|
| Back to top |
|
|
keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
|
| Posted: Fri May 15, 2009 9:28 pm Post subject: |
|
|
Danny,
Are your puzzles minimal? Meaning that, if any one initial clue is deleted, the puzzle has multiple solutions?
(I believe it is not possible to delete an initial clue and get a puzzle that has no solutions. That seems obvious.)
(Remarkably, at least when you first hear about it, is is possible to add an initial clue and make a puzzle more difficult.)
Keith |
|
| Back to top |
|
|
daj95376
Joined: 23 Aug 2008
Posts: 3854
|
| Posted: Fri May 15, 2009 10:47 pm Post subject: |
|
|
| keith wrote: | Danny,
Are your puzzles minimal? Meaning that, if any one initial clue is deleted, the puzzle has multiple solutions?
(I believe it is not possible to delete an initial clue and get a puzzle that has no solutions. That seems obvious.)
(Remarkably, at least when you first hear about it, is is possible to add an initial clue and make a puzzle more difficult.)
Keith |
Keith,
My puzzles aren't minimal for two (primary) reasons.
1) They're symmetric across the \-diagonal. Symmetric puzzles are seldom minimal.
2) The way I generate puzzles causes it to stop eliminating cells if the techniques needed to solve the puzzle exceed the techniques I allow. This means that clues/givens can sometimes still be removed, but the difficulty level of the puzzle increases beyond a set threshold.
Regards, Danny |
|
| Back to top |
|
|
keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
|
| Posted: Sat May 16, 2009 12:37 am Post subject: |
|
|
Danny,
Interesting. I did my best programming in Fortran 66 and 77!
It is my impression that others start from a solution grid, and then add (symmetric) initial clues until they get a feasible puzzle.
The symmetry thing is actually aesthetic, not needed for a good puzzle. (You know that!) You may notice that the Free Press puzzles I post are not quite symmetric, while the "patterns game" puzzles on sudoku.com have patterns that are sometimes quite stunning.
I think I mean that if your algorithm were to ADD (symmetric) cells while certain solving techniques were still required, you would have puzzles with fewer singles (but more initial clues).
Keith |
|
| Back to top |
|
|
daj95376
Joined: 23 Aug 2008
Posts: 3854
|
| Posted: Sat May 16, 2009 4:44 am Post subject: |
|
|
| keith wrote: | Danny,
Interesting. I did my best programming in Fortran 66 and 77!
It is my impression that others start from a solution grid, and then add (symmetric) initial clues until they get a feasible puzzle.
The symmetry thing is actually aesthetic, not needed for a good puzzle. (You know that!) You may notice that the Free Press puzzles I post are not quite symmetric, while the "patterns game" puzzles on sudoku.com have patterns that are sometimes quite stunning.
I think I mean that if your algorithm were to ADD (symmetric) cells while certain solving techniques were still required, you would have puzzles with fewer singles (but more initial clues).
Keith |
Keith,
I'm not sure what others do to generate puzzles. I've seen comments on how some generate puzzles, but the descriptions are more of an overview.
When I wrote my first solver, I also wrote a puzzle generator. The latter starts with a completed grid and hides cells until a unique solution no longer exists. This occurs many times for the completed grid, and I save the most difficult puzzle from those generated. It was my hope that this approach would result in a very difficult puzzle that still had a unique solution. The results were good but not great.
When I joined this forum, I adapted this approach to not generate puzzles more difficult than a specified set of solving techniques. I've been modestly successful.
I am still working on improving and upgrading the techniques in my current solver. I plan to create a new puzzle generator once I'm satisfied with my new solver.
Regards, Danny
{ ##### This Space Reserved for an Example ##### }
| Code: | Example of Unconstrained Puzzle
+-----------------------+
| 4 . . | . . . | . 5 . |
| . 1 . | 2 . . | . . 7 |
| . . 5 | . 1 3 | . . 8 |
|-------+-------+-------|
| . 5 . | 9 8 . | . . . |
| . . 2 | 7 . . | . . . |
| . . 7 | . . 2 | 8 . 1 |
|-------+-------+-------|
| . . . | . . 4 | . . . |
| 7 . . | . . . | . 8 . |
| . 8 3 | . . 7 | . . . |
+-----------------------+
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
