dailysudoku.com

[keith]

Here is today's puzzle:

[Marty R.]

This one was solved pretty quickly. All basic stuff, with a Type 4 thrown in.

[keith]

I thought this one was interesting.

First, if you ignore the Unique Rectangle, it can be solved with an XY-wing.

Second, you can exploit the UR in a number of ways, if you do not do all the other basic eliminations first. I first found the UR at this point:

[David Bryant]

Hi, Keith!

I worked this one in the newspaper before I saw your post. I managed to get through it without any pencil marks, but I did rely on the "UR" in r78c59 to do it. My analysis wasn't nearly as sophisticated as yours, though.

After doing the basic stuff I arrived here.

[Marty R.]

[TKiel]

The program I use (and I'm assuming others are similar) has an 'undo' buttom, which I can use to show the pencilmarks at any particular spot in my solving process. It's especially nice if I want to disect the puzzle (which I usually don't since I'm in the least resistance solving club also), because, once it is solved (if I get that far) I can go back to the beginning, see what cell was solved or number was excluded at each subsequent step, without having to remember how I did it, while looking for alternative methods if I so desire.

[David Bryant]

[keith]

Marty (and others),

I solve puzzles with pencil and paper.

But, before I post an analysis of a puzzle, I use Sudoku Susser to check my logic and to generate the puzzle grids to post as "code". Susser has a log from which you can cut and paste; It also has an option to log the current puzzle at every move.

Susser also has the capability to save the state of a puzzle, but it is a little cumbersome (each state is a different file). Mostly, I just keep the initial puzzle. When solving, you have the option to go back one step (and one more step, etc.), or to reset the puzzle to its initial position.

What I am trying to say is, yes, you can go back, but it does not implement "backtracking" as a solution technique.

I also use Susser to help solve puzzles when I get stuck. What I usually find is that there is some bookkeeping error in my pencilmarks. Or, stupid me, I did not see that 11-link chain!

I can't speak for other software, but an application like Susser is an excellent learning tool. Not to solve puzzles with, but to re-examine how you solved (or not) a particular puzzle.

Keith

[Marty R.]

Keith,

I had downloaded the Susser some months ago, at your recommendation and with some assistance. But it was for reading about techniques, not using as a tool.

At any rate, I haven't looked at it lately, but I recall it's about a 95-page document and I've looked through it a couple of times and coudn't see anything that looked like a computer solver, or whatever it's called. But then, I'm no computer genius either.

[keith]

Marty,

When you download Sudoku Susser, you get a zip file. When you unzip it, you will find the manual (the PDF document you describe) and also an executable, sudoku.exe. This is the computer program.

Just unzip the files, and put them in some directory. Double-click on sudoku.exe, and the software will run. If you need further help, we can do it by mail.

Keith

[Marty R.]

OK, I did all that and found the program. If I have the time and inclination to get through the voluminous instructions, it'll be awhile.

Thank you.

P.S. I wonder what a "susser" is. Other than something that susses.

[keith]

1. sussed
Generally used as friendly replacement of "figured out", "worked out" or "done".

"You've got it all sussed out don't you, Mac?"


2. sussed

Discovered the answer. Achieved individual enlightenment regarding a current problem or dilema.

Ah, I think I've sussed it...

[Marty R.]

Two dozen lashes with a wet noodle for me for not checking a dictionary first, which is odd, since I'm a frequent dictionary user.

Friday, while out on the lake, if we're fortunate enough to locate some bass, I'll impress my partner and say, "yeah Jeff, I think we've got these bass sussed out."