FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in          Games  Calendar Log in to check your private messages    Inherent difficulty?          Sudoku Programmers Forum Index -> The mathematics of sudoku View previous topic :: View next topic   Author Message cobnut Joined: 30 May 2008 Posts: 4 : Items Posted: Tue Jun 03, 2008 9:08 am    Post subject: Inherent difficulty? This is a question to which I should really know the answer, but I'm afraid I don't. Is any given order 3 suduko grid more difficult to solve than another, regardless of the givens? Or is it only the givens that determine difficulty? Part of me suggests that certain arrangements of the numbers within the grid might make them inherently easier or harder to solve, but another part of me says that's rubbish. Does my question make sense? Jon Back to top Jean-Christophe Joined: 19 Mar 2006 Posts: 126 : Location: Belgium Items Posted: Tue Jun 03, 2008 3:05 pm    Post subject: The number and pattern of the givens has very few influence on the difficulty. 1. Some of the 17 clues minimal found by Gordon Royle can be solved with singles only. 2. The Pattern Game at Sudoku Payers' Forum demontrates the vast range of difficulties for the same pattern. _________________ Jean-Christophe "When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes. Back to top gsf Joined: 18 Aug 2005 Posts: 411 : Location: NJ USA Items Posted: Tue Jun 03, 2008 3:51 pm    Post subject: Re: Inherent difficulty? cobnut wrote: Is any given order 3 suduko grid more difficult to solve than another, regardless of the givens? Or is it only the givens that determine difficulty? Part of me suggests that certain arrangements of the numbers within the grid might make them inherently easier or harder to solve, but another part of me says that's rubbish. interpreting grid as a solution grid (81 clues) then there are many minimal puzzles that can be derived from the grid the question is then: how much influence does a particular solution grid have on the ratings of its derived grids? I'm pretty sure the answer is don't know but we do know that a solution grid can influence some properties of its derived puzzles e.g., the unavoidables control the minimum number of clues and there are ways to determine if a particular solution grid contains 17 clue derived puzzles 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