Some interesting ideas Michael, keep them coming.
With regards to the code-snippet you posted, this kind of
'mark-to-prevent-double-work' type of construction is very common in
computer-Go. Looping over the complete array to set the initial value
is very expensive and totally avoidable.
The same functionality could be achieved by the following:
marker++; // This is an int initialised to zero somewhere in
the beginning of your program.
double weight = 1.0;
double weightDelta = 2.0 / (ctm - savctm + 1);
for (int i = savctm; i < ctm; i += 2)
{
int mv = mvs[i] & MASK;
if (credit[mv]!=marker) // Note that credit[] is now an
array of int instead of boolean
{
wins[mv] += weight * sc;
hits[mv] += weight;
credit[mv] = marker; // do not award credit for this move
again
}
This is slightly simplified, just so you get the idea. To make it 100%
safe you need to check if marker==0 after the increment and clear the
credit array. This is so common I use a little helper class that wraps
this fucntionality for me, called BoardMarker. The code would look as
follows:
boardMarker.getNewMarker(); // BoardMarker is allocated
somewhere at the beginning of the program: BoardMarker boardMarker =
new BoardMarker();
double weight = 1.0;
double weightDelta = 2.0 / (ctm - savctm + 1);
for (int i = savctm; i < ctm; i += 2)
{
int mv = mvs[i] & MASK;
if (boardMarker.notSet(mv))
{
wins[mv] += weight * sc;
hits[mv] += weight;
boardMarker.set(mv); // do not award credit for this move
again
}
Disclaimer, my code is not like this (yet) so I didn't try this for
real. But it should work.
On Tue, Oct 28, 2008 at 8:43 PM, Michael Williams
<[EMAIL PROTECTED]> wrote:
> for (int mv = 0; mv < NNN; mv++)
> {
> credit[mv] = true; // initial assumption is that credit is
> awarded for any move
> }
> double weight = 1.0;
> double weightDelta = 2.0 / (ctm - savctm + 1);
> for (int i = savctm; i < ctm; i += 2)
> {
> int mv = mvs[i] & MASK;
>
> if (credit[mv])
> {
> wins[mv] += weight * sc;
> hits[mv] += weight;
> credit[mv] = false; // do not award credit for this move
> again
> }
>
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