FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in          Games  Calendar Log in to check your private messages    Error whe Applying Unique Rectangle Type I          Sudoku Programmers Forum Index -> Solving sudoku View previous topic :: View next topic   Author Message NewUrbanBlues Joined: 22 Oct 2006 Posts: 36 : Items Posted: Sun Jan 07, 2007 6:49 pm    Post subject: Error whe Applying Unique Rectangle Type I Hello I hit an error when using the Unique Rectangle Type I Here is the board 7 53 4 | 6 1 59 | 8 39 2 53 6 9 | 53 8 2 | 7 4 1 1 8 2 | 7 39 4 | 39 5 6 ---------------------------------------- 2 579 6 | 8 4 3 | 1 79 59 359 4 1 | 59 2 7 | 6 8 359 8 3579 57 | 1 59 6 | 2 379 4 ----------------------------------------- 6 1 57 | 4 359 589 | 39 2 78 59 2 8 |359 7 1 | 4 6 39 4 79 3 | 2 6 89 | 5 1 78 There is a Unique Rectngle Type I with R3C5 - R3C7 - R7C5 - R7C7. According to the UR Type 1 rule, I can remove the candidate 5 from the cell R7C5.... Here is the board solution: 734615892 569382741 182794356 256843179 341927685 897156234 615438927 928571463 473269518 Clearly R7C5 is 3 ... Oops UR Type 1 removes 3 and 9 ... Ok, there could be other thinhs to do, as an XWings. I wonder why the UR Type 1 rule gives me a false result !!!!!! Thanks for any clues explaining this ... Thierry Back to top daj95376 Joined: 05 Feb 2006 Posts: 349 : Items Posted: Sun Jan 07, 2007 7:27 pm    Post subject: You made the classic error of using Unique Rectangles -- spanning more than one chute!!! A UR Type 1 has all cells in the same chute; i.e., two of three boxes. Your cells span two chutes and four boxes! Code:  *-----------------------------------------------------------*  | 7     35    4     | 6     1     59    | 8     39    2     |  | 35    6     9     | 35    8     2     | 7     4     1     |  | 1     8     2     | 7    *39    4     |*39    5     6     |  |-------------------+-------------------+-------------------|  | 2     579   6     | 8     4     3     | 1     79    59    |  | 359   4     1     | 59    2     7     | 6     8     359   |  | 8     3579  57    | 1     59    6     | 2     379   4     |  |-------------------+-------------------+-------------------|  | 6     1     57    | 4    #359   589   |*39    2     78    |  | 59    2     8     | 359   7     1     | 4     6     39    |  | 4     79    3     | 2     6     89    | 5     1     78    |  *-----------------------------------------------------------* Last edited by daj95376 on Sun Jan 07, 2007 7:32 pm; edited 1 time in total Back to top Ruud Site Admin Joined: 17 Sep 2005 Posts: 708 : Location: Netherlands Items Posted: Sun Jan 07, 2007 7:31 pm    Post subject: For more info: http://www.sudopedia.org/wiki/Unique_Rectangle Ruud Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         Sudoku Programmers Forum Index -> Solving 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