On Tue, 2007-06-05 at 13:12 -0700, Peter Drake wrote: > > So I'm only temporarily maintaining a list of illegal but unoccupied > > points - this list gets "discarded" as soon as a legal move is > tried. > > Does that mean you have to regenerate the list every move?
I keep the list of un-occupied points - but the tiny list of illegal points gets regenerated from move to move. However, this list is so tiny that it rarely amounts to more than 0 moves. Near the end of the game it could get bigger, but if it does it is starting to save some real time. I think this is win/win. > > What you are doing is to avoid the call to the random number > generator > > by > > trying the moves as a circular list. This may be faster, but it's > > biased, perhaps the bias is insignificant enough that it doesn't > have > > an impact on the strength. > > No, I pick a random point in the list every time, so there's still a > call to the random number generator. Just proceeding through the > list > would be horribly biased (unless the list were pre-shuffled, as I > was > doing previously). So it's possible that in a degenerate case you could pick many illegal moves over and over again. Technically, you could get into an infinite loop if the period of your RNG was such that a legal move could not get seen. But I'm being really picky :-) I am perhaps being too anal making sure I don't choose the same illegal move twice. However the code is trivial and it's not a major difficulty managing. But I'm wondering if starting at a random point in a list of unoccupied points and searching sequentially is really that terrible? Another idea I have is that when you do hit an illegal point, swap it with a random element so that this particular bias point is changed for the next move, then continue to search sequentially for a legal move. You could eliminate most of the RNG calls and the swaps. But there are probably not that many anyway. - Don _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
