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Subject: Re: question about hash tables

Author: martin fierz

Date: 13:15:58 05/08/02

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On May 08, 2002 at 15:27:33, Uri Blass wrote:

>On May 07, 2002 at 19:26:43, martin fierz wrote:
>
><snipped>
>>i used to use a two-table approach in my checkers program, with one table being
>>used for all nodes which were <N plies from the root, the other for >=N. in the
>>first table, i replaced with deeper draft only, in the second, i always
>>replaced. i changed it to a single table after finding no significant
>>difference; in the single table i have a hash bucket size of 2,
>
>I do not understand.
>
>What does a hash buket size of 2 means?

you get an index to save your hashentry to from your hashkey. instead of saving
1 entry at every index, you can save N there - N is the bucket size. the idea is
that if the bucket is full, you can choose one of the N entries you want to
overwrite - instead of overwriting what may have been a valuable entry, you look
which of them is the least valuable, and overwrite that one.

>Note that I do not understand what is the reason for using 3 integers for
>depth,flags and value when it is possible to compress these 3 numbers to a
>single 32 bit integer in order to have more entries in the hash tables.
just so it's clear...

aloha
  martin



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