FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in          Games  Calendar Log in to check your private messages    How small is the smallest X-sdoku?          Sudoku Programmers Forum Index -> The mathematics of sudoku View previous topic :: View next topic   Author Message m_b_metcalf Joined: 13 Mar 2006 Posts: 210 : Location: Berlin Items Posted: Thu Mar 16, 2006 11:51 pm    Post subject: How small is the smallest X-sdoku? In another thread (http://www.setbb.com/sudoku/viewtopic.php?t=771&mforum=sudoku) I posted an X-sudoku with only 15 givens. Here is another: Code:                           8   9              4                  4              7                     1            2              9  3  4         8        3                                                3  7                                          5 Has anyone have any idea how much smaller one can go? Thanks, Mike Metcalf Back to top Ruud Site Admin Joined: 17 Sep 2005 Posts: 708 : Location: Netherlands Items Posted: Thu Mar 16, 2006 11:57 pm    Post subject: How about this one, Mike? Code: . . 4|. . .|. . . . . 1|. . .|8 . . . . .|. . .|. . 7 -----+-----+----- . . .|. . .|. . . . 9 .|. 5 .|. 2 . . 7 .|. . .|. . . -----+-----+----- . . .|6 . .|. . . . . 8|3 . .|1 . . . . .|. . .|. 4 . 13 clues, unique solution. Ruud. _________________ Meet me at sudocue.net Back to top m_b_metcalf Joined: 13 Mar 2006 Posts: 210 : Location: Berlin Items Posted: Fri Mar 17, 2006 1:24 pm    Post subject: Ruud wrote: 13 clues, unique solution. Ruud. Ruud, Thanks. I'll have to try harder! (The smallest in Monckton's book is 16, I believe.) Regards, Mike Metcalf Back to top LangPol Joined: 20 Mar 2006 Posts: 6 : Items Posted: Mon Mar 20, 2006 1:33 am    Post subject: Alas, I don't believe that there is a unique solution. e.g., 6 8 4 | 2 3 7 | 9 5 1 7 2 1 | 9 6 5 | 8 3 4 5 3 9 | 4 1 8 | 2 6 7 ------+-------+------ 4 1 5 | 7 2 3 | 6 9 8 8 9 6 | 1 5 4 | 7 2 3 3 7 2 | 8 9 6 | 4 1 5 ------+-------+------ 9 4 3 | 6 7 1 | 5 8 2 2 5 8 | 3 4 9 | 1 7 6 1 6 7 | 5 8 2 | 3 4 9 2 8 4 | 9 3 7 | 6 5 1 7 3 1 | 5 4 6 | 8 9 2 9 6 5 | 8 2 1 | 4 3 7 ------+-------+------ 4 5 3 | 7 8 2 | 9 1 6 8 9 6 | 1 5 3 | 7 2 4 1 7 2 | 4 6 9 | 5 8 3 ------+-------+------ 3 4 9 | 6 1 8 | 2 7 5 5 2 8 | 3 7 4 | 1 6 9 6 1 7 | 2 9 5 | 3 4 8 Back to top Ruud Site Admin Joined: 17 Sep 2005 Posts: 708 : Location: Netherlands Items Posted: Mon Mar 20, 2006 1:49 am    Post subject: LangPol wrote: Alas, I don't believe that there is a unique solution. e.g., 6 8 4 | 2 3 7 | 9 5 1 7 2 1 | 9 6 5 | 8 3 4 5 3 9 | 4 1 8 | 2 6 7 ------+-------+------ 4 1 5 | 7 2 3 | 6 9 8 8 9 6 | 1 5 4 | 7 2 3 3 7 2 | 8 9 6 | 4 1 5 ------+-------+------ 9 4 3 | 6 7 1 | 5 8 2 2 5 8 | 3 4 9 | 1 7 6 1 6 7 | 5 8 2 | 3 4 9 This is Sudoku-X. The diagonals also need to contain digits 1 thru 9. Ruud. _________________ Meet me at sudocue.net Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         Sudoku Programmers Forum Index -> The mathematics of sudoku All times are GMT Page 1 of 1   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