Author: Daniel Clausen
Date: 03:43:20 10/10/02
Go up one level in this thread
On October 10, 2002 at 06:20:31, Nagendra Singh Tomar wrote: >No, not really. >I have got a single one-dim array that is part of the singleton ChessBoard >structure. >If a move at ply 'x' is found to be lying on the PV (score > alpha) then I >simply do "PV[x] = this_move" without caring to copy the remaining PV from the >deeper plies, because they would have already added it to the PV array at >appropriate place in the PV array. So by the time I reach ply 'x' after >returning from ply 'x+1' I am sure that the part of the PV starting from 'x+1' >is already in place. I just add this ply's contribution to the PV. >Doing this when i reach the root, all the moves in the PV will be stored in the >one dimensional PV array. > >What do u say ? That this is a bug. :) You can't just put the moves in ply 'x+1' in this single PV-array, because if you return to ply 'x' and find out that the score here is not bigger than alpha, this variation doesn't belong to the real PV. Unfortunately you've already overwritten the old PV-moves in ply 'x+1'. Note that when returning from a search at ply 'x+1', the PV of this search is just a _potential_ PV for ply 'x'. A good page which keeps track of the PV but doesn't use the triangle PV-array is http://www.seanet.com/~brucemo/topics/pv.htm. Sargon
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.