On 29-okt-08, at 00:13, Don Dailey wrote:
The marker idea I call aging. I call the variable age because it
seems
to be more descriptive to me. Each playout has a different age
associated with it. The idea is used in persistent hash tables in
computer chess and I'm sure in other games too.
Yes, it could be seen as a form of aging. I use it for a whole lot of
different things however, including things like not double-counting
liberties, or making sure I process points only once in an area of
unknown size beforehand.
However, I seriously doubt this particular enhancement is even worth
doing in this context. It may even be difficult to measure the
speedup
it will give you. I would be surprised if you get 1/2 percent.
I don't initialize the array in a loop either, I use memset in C.
If I
did this is java I would use whatever java method is the equivalent
assuming it is optimized.
If you want to save on initialization (which is pretty fast on modern
processors anyway) you can make this a bit array instead of an int
array. Then it would initialize about 32 times faster but you would
probably spend a little more time referencing it.
If you were to profile the code, I'll bet this would be one of the
very
last sections of code you would bother optimizing. Still, if you
are a
speed freak you would probably at some point get around to doing it
just
because you can!
This could very well be true. But old habits die hard! ;-) If I can
save initialization of an array the size of a board within a loop I
always do.
And since I have the little class ready to use for cases like this it
becomes a kind of reflex. It doesn't cost anything and using the
class actually makes me less prone to making errors.
Mark
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