simon-svn: puzzles: simon

[tartarus-commits at lists.tartarus.org]

SVN root:       svn://ixion.tartarus.org/main
Changes by:     simon
Revision:       6239
Date:           2005-08-30 18:44:18 +0100 (Tue, 30 Aug 2005)

Log message (10 lines):
Implemented a couple more reasoning modes for Extreme difficulty
level: positional set elimination (which is so obvious I really
should have thought of it myself, though it's tricky to spot) and
forcing chains (which are a type of one-level proof by
contradiction, findable through a simple breadth-first search
without requiring recursion, but so ludicrously powerful that they
are able to solve _two thirds_ of grids that the pre-Extreme Solo
generated and rated as Unreasonable).

Of course this makes Unreasonable mode harder still...

Modified files:
U   puzzles/solo.c

Links:
http://www.tartarus.org/~simon-anonsvn/viewcvs.cgi?rev=6239&view=rev
http://www.tartarus.org/~simon-anonsvn/viewcvs.cgi/puzzles/solo.c?rev=6239&r1=6238&r2=6239