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**Date**: Mon, 7 Jul 1997 06:12:16 -0700 (PDT)**From**: Michael Brundage <brundage@piaf.ipac.caltech.edu>- cc: moo-cows@the-b.org
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On Tue, 1 Jul 1997, Richard Godard wrote: > Beside be carefull with the O() there are some constants that disapears and > they can't always be neglected... beside in theory hash table have O(1) > search/delete/add/etc., in practice... :) :) :) > > Welcome to the marvelous world of data structures and algorithms :) And perhaps more to the point, those O() proofs assume a certain model of computing, which may or may not apply to the world of MOO. In Mathematica, for example, most list operations are slow because Mathematica makes a copy of the list each time; other operations are very fast thanks to lazy evaluation; etc. (Similar things happen in MOO; compare the various insertion methods listappend(somelist, some element), somelist = {@somelist, someelement}, somelist = {@somelist, some elements, several, at, a time}, etc. ) Consequently the fastest algorithms in theory (which assumes the RAM model) are not always the fastest in a program such as Mathematica or MOO. Steven Skiena's book on Combinatorics in Mathematica (sorry, I don't recall the exact title) gives a nice explanation of all this. Cheers, michael brundageQipac.caltech.edu

**Re: hash & balanced trees***From*: "Robert J. Brown" <rj@eli.wariat.org>

**re:hash & balanced trees***From*: Richard Godard <janus@cam.org>

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