Getting back to shorter solutions.....
From: Shlomi Fish
Sent: Friday, November 30, 2012 2:46 AM
To: fc-solve-discuss_at_yahoogroups.com
Cc: dannyjones183_at_yahoo.com
Subject: Re: Usable Solution vs. Any Solution
Just for the record, here is the solution
that ./freecell-solver-fc-pro-range-solve currently generates (again with my
own heuristic of automoves):
<<<<<<<<<<<<<<<
shlomif[fcs]:$trunk/fc-solve/source/B$ ./freecell-solver-fc-pro-range-solve
6240 6240 1 --read-from-file
4,/home/shlomif/progs/freecell/git/fc-solve/fc-solve/source/Presets/testing-presets/mfi-with-2-more-scans.sh
-fif 10 --flares-choice fcpro --cache-limit 100000
Started at 1354272030.489860
[[Num Iters]]=1439064
[[Num FCS Moves]]=96
[[Num FCPro Moves]]=56
[[Start]]
8a 8b 2h 8c 8d b3 63 1b 18 13
85 d5 6d 68 61 6h b1 5b 5h 8h
28 24 2h 54 5h 62 d2 85 36v4 3d
38 32 35 a5 35 57 53v2 42 4a 4b
45 1c 1h 1a 1h 5h 45 74 7h 85
68 6h a6 7a 7h 23
[[End]]
Reached Board No. 6240 at 1354272039.679491 (total_num_iters=1439064)
>>>>>>>>>>>>>>>
RESPONSE:
One of the most powerful components of a solver is how well it sorts moves.
Pruning is very important, but of the two strategies, sorting is the key.
For example, my current version also solves #6240 in 56 steps (but with a
very different solution). It took 928 iterations (moves investigated) with
109 backups. On the average, it solves games in under 50 steps, and about
40% of them with no backup at all. I believe this is due to choosing a good
move at each step.
One of the things I noted in Shlomi's solution was that card->home moves
were given too high a priority (my current solver suffers from this as well,
but maybe to a lesser extent). I can reduce my solution to 51 steps, and
Shlomi's to 47 steps by avoiding unnecessary card->home moves using
the heuristic mentioned below.
I've found that giving a high priority to moves that attempt to expose a
WKR automove is a good heuristic for shorter solutions. I noted that the
two non-Horne automoves in Shlomi's solution were WKR.
-Gary Campbell
Received on Fri Nov 30 2012 - 10:49:40 IST