Fapanosss: A Fast, Portable, Animated, Open-source Sudoku Solver in your Browser

Fapanosss

Mayank Lahiri

mlahiri cs uic edu (insert 'at' after first word to mail me)

[ Motivation ] [ Features ] [ Settings ]
When comparing against other solvers, please keep in mind that (a) this is Javascript, (b) pseudo-threading in Javascript is more of curiosity than a real solution (SLOOW!) and (c) I make no effort to detect boards with more than one solution.

Pseudo-threading in Javascript (browser remains responsive while solving)
Entirely self-contained (JS+HTML+CSS) in a single HTML file (save it to your hard drive, use it offline in a plane!)
Two-phase solver (faster on "easy" instances, uses logic first, then brute force)
Objective difficulty rating -- (log of expected size of search tree of nontrivial solution)
Can detect boards with no solution (eventually)

Randomize cell order when solving (no real good reason for doing this)
Iterations per timeslice: (decrease for slower computers)
Sleep between timeslices (ms): (increase for better browser responsiveness)

Instance difficulty:

Test cases:

Name	Human difficulty	Fapanosss difficulty	Solution time	Description
	Boring	0	0s	Complete board -- sanity check.
	Easy	56.54	0.11s	Solvable using pure logic.
	Hard	68.2	0.131s	Mostly logic, some brute force.
	Hard	82.03	0.329s	A hard puzzle from here
	Hard	83.47	0.08s	No freebies, must brute force from the start.
	Hard	89.98	0.107s	An alternate version of Al Escargot, somewhat easier.
	Very hard	92.25	3.37s	Looks about as hard as it gets.
	Inhuman	96.01	45.7s	Another hard one. Thanks to Tarek on the sudoku.com forum
	Inhuman	96.92	100.1s	Supposedly hardest Sudoku possible.

Messages:

Fapanosss v2.0