On Wed, 21 Sep 2005 [EMAIL PROTECTED] wrote: > Excellent strategies are provided by Dan Rice's blog: > http://sudokublog.typepad.com/sudokublog/2005/08/two_and_three_i.html
There's an interesting remark in this post: http://sudokublog.typepad.com/sudokublog/2005/08/where_do_sudoko.html "Some Sudoku generators skip the step of generating a board altogether. It's enough to place some random numbers in the board and see if it has a solution. For a backtracking solver, which can solve puzzles very quickly, ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the time wasted analyzing impossible sets of clues will be minor. For a human-style solver, it seems reasonable to exclude the possibility of self-contradictory clues by first generating a consistent underlying board." He seems to think that backtrackers are faster than reasoners. That's somewhat counter-intuitive; i wonder if it's really true. It would certainly be rather sad if it was. > You won't find any better solver than this: > http://sudoku.sourceforge.net/ That's a fairly straightforward backtracker. In fact, it's the solver which inspired me to write mine - which i believe has a more sophisticated heuristic (i haven't compared them formally, but my heuristic sophistication estimation heuristic - which is itself, of course, fairly sophisticated - suggests that it is). Clearly, what we need is a sudoku solver shootout. tom -- everything from live chats and the Web, to the COOLEST DISGUSTING PORNOGRAPHY AND RADICAL MADNESS!! -- http://mail.python.org/mailman/listinfo/python-list
