simon-git: puzzles (master): Simon Tatham

[Commits to Tartarus CVS repository.]

TL;DR:
  cca302c Improve the Flood solver.

Repository:     git://git.tartarus.org/simon/puzzles.git
On the web:     http://tartarus.org/~simon-git/gitweb/?p=puzzles.git
Branch updated: master
Committer:      Simon Tatham <anakin at pobox.com>
Date:           2015-01-15 20:36:42

commit cca302c01b7b331c280ec885d783d673a0c951c3
web diff http://tartarus.org/~simon-git/gitweb/?p=puzzles.git;a=commitdiff;h=cca302c01b7b331c280ec885d783d673a0c951c3;hp=202e7fecfdac09b791b204cde464f09f9165f55b
Author: Simon Tatham <anakin at pobox.com>
Date:   Thu Jan 15 20:21:05 2015 +0000

    Improve the Flood solver.
    
    Previously it simply chose every move based on the static evaluation
    function 'minimise the pair (longest shortest-path to any square,
    number of squares at that distance)'. Now it looks three moves ahead
    recursively, and I've also adjusted the evaluation function to tie-
    break based on the number of squares brought to distance zero (i.e.
    actually in control).
    
    The result isn't an unconditional improvement on the old solver; in a
    test run based on 'flood --generate 1000 12x12c6m0#12345' I found that
    57 out of 1000 grids tested now had longer solutions. However, about
    three quarters had shorter ones, and solutions are more than a move
    shorter on average.

 flood.c |  180 ++++++++++++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 139 insertions(+), 41 deletions(-)