Sudoku Players' Forums

[RW]

Terve Arto

Just read about your remarkable puzzle in my local newspaper. I don't want to post other peoples puzzles here, published or not, but I was hoping that maybe you want to share it with the sudoku community. It should give people something to think about for a while, at least Sudoku Explainer needs a little fix - there's a typo in the phrase "The Sudoku Emplainer failed to solve this Sudoku using logical rules only"...

I think I understand better now the point of your technique. A technique that finds the solution to all puzzles is nothing new, but if it can find the shortest solution, then it could be something quite revolutionary. At least I haven't seen anything like that before. I don't quite understand your terminology though. Around here the word 'link' is usually used for strong or weak links between 2 candidate cells. It seems you use the word link in a totally different meanig. Could you explain exactly what the links indicate, preferably with the help of a 4 or 5 link AIroot elimination, in such a way that everybody can understand what a n link elimination is?

Also, if you wish to share your methods for creating hard sudokus, I think many people here would appreciate that.

RW

[ronk]

[ravel]

ArtoI,

since you are not very loquacious, let me guess, what you are doing.
Given a grid, where the arsenal of implemented techniques dont help, test each candidate:

Set the cell to the candidate and apply all placements and eliminations that can be done now simultaneously as one "link" (batch move).

Doing this e.g. for 5 in r9c5 in the starting grid you can apply singles, locked candidates and x-wing in the first link, singles pair, locked candidates and coloring in the second. Then singles will be enough in the third to kill the last 9 in block 1 and column 1 in the third link.

For the solution make all eliminations/placements with the minimum number of "links".

Assuming this, i wondered, how much "links" my first step in the first solution would take: r7c8<>8 needs 5 "links" with common advanced techniques (then i have two 4's in column 8 - but i saw now, you need 6 links for HG8 ??).

This method would not reflect better than others, how human solvers would try to solve a hard puzzle, but it would provide another rating, namely the sum of links needed for the solution (and it can be calculated a lot faster than the RMS).

Since i cannot calculate it with my program, i still wonder, what the sum of needed "links" would be for the 3 solutions i got from my program for your puzzle.

[ArtoI]

[ravel]

Thanks, Arto,

your explantion seems to confirm, what i expected, what you mean with a (elimination) link.

Since i saw, that you have an own rating system and mine is overstrained by the super hard puzzles posted in the hardest thread in the last days (after i showed yours there, the first one, my program could not solve), i would be very interested, how you would rate them.

[RW]

[gsf]