Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: hash table collisions

Author: Bruce Moreland

Date: 09:54:15 01/15/00

Go up one level in this thread


On January 15, 2000 at 09:40:51, James Swafford wrote:

>If you use 20 bits to probe, why not just store the other 44 bits in the
>table as a checksum?  You already know the other 20 bits match....

What I do in mine is I use the bottom however many bits to probe, and I store
the top 32 bits.  So I lose some bits unless my table hits 2^32 elements, which
is not likely for a while at least.

The reason I told the original poster to store all 64 is that I didn't want to
write something more complicated.  Storing all 64 would work, it is easy to do,
and it may not be worse than any other solution.

But the answer to your question is more complicated.  There isn't such a thing
as a 44-bit standard data type, so you will end up storing and comparing several
chunks, unless you get tricky and use a union, which would let you use the
redundant bits for something else.

Sound like it's extra code and a little extra complication in any case.

bruce



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.