There are longer cycles that can occur but I have never encountered any that didn't naturally resolve themselves in the playout.
Zobrist having is cheap to compute (one xor if no stones were captured). Comparing the resulting number against the others is also cheap. The hash is also helpful for handling transpositions in the search tree. https://en.m.wikipedia.org/wiki/Zobrist_hashing On Aug 30, 2015 9:17 PM, "Minjae Kim" <xive...@gmail.com> wrote: > Yes, but to 'remember' the prior board state, doesn't the program have to > store the whole board position per every turn by whatever means including > Zobrist hashing that you suggested? > > After that, the program has to search whether the current position matches > any of the previous ones. You said 3 is enough for triple kos, but as far > as I know aren't there some rare repeating positions with a cycle longer > than 3? > > But anyway solving the problem this way seems too expensive to me. > 2015. 8. 31. 오전 9:59에 "Jason House" <jason.james.ho...@gmail.com>님이 작성: > >> Triple ko can be detected by remembering the prior three board states. A >> zorbist hash value should be good enough to detect a repeat. >> On Aug 30, 2015 8:46 PM, "Minjae Kim" <xive...@gmail.com> wrote: >> >>> I finally managed to build a program that can produce a sequence of >>> random legal go moves. One problem I found recently is that it rarely never >>> ends a game because of triple ko, especially on small boards. >>> >>> One possible solution would be saving every board position that has >>> occurred and searching for a match before generating a move. But this >>> doesn't sound like an efficient solution at all. >>> >>> How do you handle this problem? >>> >>> Also as a side question, white constantly seems to have a better winning >>> rate in any board size larger than 9x9 with komi greater than 6 under area >>> scoring in completely random games; is this natural? >>> >>> _______________________________________________ >>> Computer-go mailing list >>> Computer-go@computer-go.org >>> http://computer-go.org/mailman/listinfo/computer-go >>> >> >> _______________________________________________ >> Computer-go mailing list >> Computer-go@computer-go.org >> http://computer-go.org/mailman/listinfo/computer-go >> > > _______________________________________________ > Computer-go mailing list > Computer-go@computer-go.org > http://computer-go.org/mailman/listinfo/computer-go >
_______________________________________________ Computer-go mailing list Computer-go@computer-go.org http://computer-go.org/mailman/listinfo/computer-go
