I was waiting for this one... :)
Joel
On Wed, May 14, 2008 at 1:57 PM, Hideki Kato <[EMAIL PROTECTED]> wrote:
>
> Álvaro Begué: <[EMAIL PROTECTED]>:
>
> >Ooops! I hit sent before I finished writing the pseudo code. Sorry.
> >
> >int pick(Move *empties, int num_empties) {
> > int num_candidates = num_empties;
> > int picked;
> >
> > while(1) {
> > picked = rand()%num_candidates;
>
> This code introduces few bias unless num_candidates is a power of two,
> though.
> #Assuming rand() returns [0 .. power of two).
>
> -Hideki
>
>
>
> > if(!acceptable(empties[picked])) {
> > num_candidates--;
> > swap(empties[picked],empties[num_candidates]);
> > }
> > else
> > break;
> > }
> > return picked;
> >}
> >
> >
> >
> >On Tue, May 13, 2008 at 1:57 PM, Álvaro Begué <[EMAIL PROTECTED]> wrote:
> >> On Tue, May 13, 2008 at 1:51 PM, Mark Boon <[EMAIL PROTECTED]> wrote:
> >> >
> >> > On 13-mei-08, at 14:10, Álvaro Begué wrote:
> >> >
> >> >
> >> > What others do is the right thing to do. Your method will introduce
> >> >
> >> > some biases.
> >> > Could you elaborate what bias it could lead to? I also do the same as
> Jason.
> >> > I did consider the possibility of a bias but couldn't immediately
> think of
> >> > one.
> >>
> >> This has been explained already. After the first eye appears on the
> >> board, the first empty point after the eye has a probability of being
> >> picked that is twice the probability of any other empty point.
> >>
> >>
> >> > What good does moving it to the end of the list do? Next time around
> it's
> >> > just as likely to be picked as when left in place. Or do you only
> process
> >> > the 'end' after the 'front' moves are all tried?
> >>
> >> You move it to the end and you reduce the number of candidates by one.
> >> The code is roughly this:
> >>
> >> int pick(Move *empties, int num_empties) {
> >> int num_candidates = num_empties;
> >> int picked;
> >>
> >> do {
> >> picked = rand()%num_candidates;
> >> num_candidates--;
> >> } while(!acceptable(empties[picked]);
> >>
> >> return picked;
> >> }
> >>
> >>
> >> Álvaro.
> >>
> >_______________________________________________
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> >http://www.computer-go.org/mailman/listinfo/computer-go/
> --
> [EMAIL PROTECTED] (Kato)
>
>
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