Sudoku Players' Forum (clone)

Optimization Partner is announcing a fail-safe sudoku solver. Try it on
www.optimizationpartner.com/sudoku.

Are there any other solvers which guarantee solution?

I think essentially all solvers are guaranteed to find the solution for any proper puzzle (i.e., one with a unique solution). Yours is the first I've seen to not only come up with one of the solutions if you put in a puzzle with more than one answer, but also to give you an answer if you enter a completely invalid set of numbers. (You can fill the grid with 3s if you want and it'll still give a 'solution' to it, by replacing 72 of them.) To be honest though, I can't see any reason why you'd want a solver to do this rather than just tell you that what you've typed in is invalid.

Go to http://www.sudoku.com/ and try some of their great puzzles. You can choose one of their grids or put in your own, get clues, do a 'sweep' to fill in "pencil marks", or get the solution directly. You can also check whether a grid is legitimate and has only one solution. With a little guesswork, you could even create your own Sudoku grids. There's also a vault containing the last 15 days' puzzles, of varying difficulty, from 'delicious', via 'pernicious' and 'malicious', to 'atrocious' (and 'atrocious' really can be just that at times).

Our algorithm has not failed so far, and seems to take about the same time to solve all instances. I think it is very competitive.

Sumoku wrote:Go to http://www.sudoku.com/ and try some of their great puzzles. You can choose one of their grids or put in your own, get clues, do a 'sweep' to fill in "pencil marks", or get the solution directly. You can also check whether a grid is legitimate and has only one solution. With a little guesswork, you could even create your own Sudoku grids. There's also a vault containing the last 15 days' puzzles, of varying difficulty, from 'delicious', via 'pernicious' and 'malicious', to 'atrocious' (and 'atrocious' really can be just that at times).

You spelled your own website url wrong -- its http://www.sudokusan.com/