FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in          Games  Calendar Log in to check your private messages    Checking for uniqe solution Goto page Previous  1, 2          Sudoku Programmers Forum Index -> Setting sudoku View previous topic :: View next topic   Author Message lkSudoku Joined: 16 May 2009 Posts: 60 : Items Posted: Fri Nov 27, 2009 5:20 pm    Post subject: Of course the algorithm I suggested is not optimized nor quick, I only tried to answer the question in the beginning of the thread and suggest a proof of correctness What I do in my program is as follows: In order to check for multiple solutions, I first try to solve while allowing backtracking and using the fastest solving methods; once a solution is found, I continue to solve with backtracking as if the solution was an error until either there is another solution (and the previous solution is not unique) or there is no other solution thus the first solution is unique When performing backtracking I always try one of the cells with minimal number of candidates (with more than one candidate) to decrease the number of guesses Back to top sudoking Joined: 20 Oct 2009 Posts: 40 : Items Posted: Sat Nov 28, 2009 12:42 pm    Post subject: Lunatic wrote: You can check the "checkuniqueness" routine within the c code from my random sudoku generator example at http://users.telenet.be/mpq/sudoku/random_sudoku_generator.c I used that one for a while in my generator. However, I replaced it with a modified version of the bb_sudoku algorithm, which was much faster. Back to top Lunatic Joined: 11 Mar 2007 Posts: 166 : Location: Ghent - Belgium Items Posted: Sat Nov 28, 2009 4:08 pm    Post subject: sudoking wrote: Lunatic wrote: You can check the "checkuniqueness" routine within the c code from my random sudoku generator example at http://users.telenet.be/mpq/sudoku/random_sudoku_generator.c I used that one for a while in my generator. However, I replaced it with a modified version of the bb_sudoku algorithm, which was much faster. I know that Brian has a much better algorithm, but I wanted to provide a C code example with a low threshold, especially for newbies. Furthermore, I'm not used to write C code, I prefer Visual Basic, but VB has not the same capabilities as C/C++. The C code is in fact a translation from my VB code. Maybe I will, someday, when I'm retired , switch to C/C++, I do have the Visual Studio suite. _________________ Marc ~~~<><~~~<><~~~<><~~~<><~~~ Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         Sudoku Programmers Forum Index -> Setting sudoku All times are GMT Goto page Previous  1, 2 Page 2 of 2   Jump to: Select a forum Sudoku----------------Solving sudokuSetting sudokuProgramming sudokuThe mathematics of sudokuExotic sudoku Library----------------PuzzlesSoftwareSudoku elsewhere Not sudoku----------------Random thoughtsForum feedback  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum   Powered by phpBB © 2001, 2005 phpBB Group Igloo Theme Version 1.0 :: Created By: Andrew Charron