From 944997d2f936150d8efbaba6dcb3e237b5658761 Mon Sep 17 00:00:00 2001 From: Simon Tatham Date: Sat, 7 May 2005 12:30:29 +0000 Subject: Aha, here's a nice easy way to generate really hard puzzles. Added the missing fifth difficulty level to Solo: `Unreasonable', in which even set-based reasoning is insufficient and there's no alternative but to guess a number and backtrack if it didn't work. (Solutions are still guaranteed unique, however.) In fact it now seems to take less time to generate a puzzle of this grade than `Advanced'! [originally from svn r5756] --- puzzles.but | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'puzzles.but') diff --git a/puzzles.but b/puzzles.but index 1e6c0fa..7d90f43 100644 --- a/puzzles.but +++ b/puzzles.but @@ -691,9 +691,10 @@ particular, on difficulty levels \q{Trivial} and \q{Basic} there will be a square you can fill in with a single number at all times, whereas at \q{Intermediate} level and beyond you will have to make partial deductions about the \e{set} of squares a number could be in -(or the set of numbers that could be in a square). None of the -difficulty levels generated by this program ever requires making a -guess and backtracking if it turns out to be wrong. +(or the set of numbers that could be in a square). At +\q{Unreasonable} level, even this is not enough, and you will +eventually have to make a guess, and then backtrack if it turns out +to be wrong. Generating difficult puzzles is itself difficult: if you select \q{Intermediate} or \q{Advanced} difficulty, Solo may have to make @@ -738,6 +739,8 @@ parameters: \b \cq{da} for Advanced difficulty level +\b \cq{du} for Unreasonable difficulty level + So, for example, you can make Solo generate asymmetric 3x4 grids by running \cq{solo 3x4a}, or 4-way rotationally symmetric 2x3 grids by running \cq{solo 2x3r4}, or \q{Advanced}-level 2x3 grids by running -- cgit v1.1