how to measure difficulty of grid -- reference to hard grids

Programs which generate, solve, and analyze Sudoku puzzles

how to measure difficulty of grid -- reference to hard grids

Postby jmwismer » Sat Nov 19, 2005 9:24 pm

Hi there,

I am working on a way to measure difficulty of grids. I am currently using SUDOKUjm (on since it gives stats as to how many different actions have been used to sove a grid. Several "difficult" grids turn out to be solved with only one or two actions (Clear singles / clear doubles), but the real tough ones need 4, 5 or 6 actions to be solved.

Can anyone direct me to a source of perceived super-tough grids? I would like to corroleate this perceived difficulty with stats provided with the software. If this works, this will enable the software to be better at producing grids of the desired difficulty level.

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Joined: 12 November 2005

Postby Pi » Mon Nov 21, 2005 5:43 pm

on my program it solves them in rounds, it fills in what it can and then enters the grid into a copy of the solver, i take into consideration how many times it has to go through the solver and how many numbers can be filled in each time
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Joined: 27 May 2005

measuring difficulty

Postby jmwismer » Wed Nov 23, 2005 9:20 pm


this looks close to what I am doing. Would you have a set of calibrated grids you could send me so I can compare? I'll send you some too in a short while, I'll be working on it over this week-end hopefully.

BTW for reference, I am counting how many times know patterns have to be called. if you are interested, you can go on > more > html help > solve to see the different patterns measured
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Joined: 12 November 2005

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