Author: Will Singleton
Date: 15:06:44 05/16/04
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On May 16, 2004 at 15:25:23, Uri Blass wrote: >On May 16, 2004 at 12:39:48, Will Singleton wrote: > >>On May 16, 2004 at 08:30:48, Uri Blass wrote: >> >>>Suppose that you have a book of 2^20 positions. >>>Suppose that you need in average 16 bytes for every position(to store >>>positions,moves and some more information like learning value for every move). >>> >>>I do not like the idea to store only positions in book and I think that the the >>>job of making all moves in book positions to find more book moves can be done in >>>the time of creating the book. >>> >>>I can think of 3 ways to find if a position is in book >>> >>>1)To do a binary search in the file that has the positions(Disadvantage:you do >>>more searches in the file relative to other ways and you basically need to probe >>>the file 20 times only to find if a position is in book). >> >>That's what I do. Easy and quick. > >I do not find it as easy. >The problem is that I do not know a special function to do a binary search in a >file and I do not like to try to write a special function for that purpose. > >There is bsearch that performs a binary search of a sorted array but I need to >perform a binary search of a sorted file because I do not like to remember all >the book in RAM. > >I start generating the book by doing qsort that performs a quick sort of an >array. > >Now I need to copy the array to a file and I think that Crafty's solution is >both faster and simpler than writing a special function to perform a binary >search on a file even in case that the book is book of positions and moves and >not book of positions like Crafty's book so alternatives 2 and 3 seems better >for me and I think that 3 is the best alternative but before I try it I prefer >to read what other people do. > >Uri Just write the function, it's not hard. I'll send you mine if you want.
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