Re: Search Algorithm

From: Sergio Basurto Juarez (sbasurtoj_at_yahoo.com)
Date: 11/15/04

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    Date: Mon, 15 Nov 2004 14:37:35 -0800 (PST)
To: debian-user@lists.debian.org

    --- Eric Gaumer <gaumerel@ecs.fullerton.edu> wrote:

    > On Mon, 2004-11-15 at 12:09 -0800, Sergio Basurto
    > Juarez wrote:
    > > First of all thanks for the note, I think I will
    > use a
    > > Hashing Table as some one suggest here, becuase in
    > > this case seems to be more suitable for the
    > problem,
    > > why am so worry about speed, is becuase is a web
    > > application in php, and it takes to long with the
    > > binarysearch algorithm, nevertheless I am testing
    > the
    > > same with Hashing Tables and it suits to what I am
    > > looking in time consuming.
    > >
    > > Also I was wondering if there were some magic
    > equation
    > > that do the trick without hashing tables, but I
    > think
    > > the time that will take me to find some one is too
    > > much so I will use hashing tables meanwhile.
    > >
    > > Thanks again.
    >
    > The binary search is O(logn) which is quite fast. It
    > reduces your
    > problem by half on each iteration (divide and
    > conquer). The problem is
    > the sort. You haven't really specified enough about
    > the problem to
    > helpful. If you need fast search times then why use
    > an array? You should
    > be using some tree structure if you really want
    > efficient search times.
    > Obviously a good hash is going to be O(1) depending
    > on your collision
    > handling.
    >
    > In this case I would suggest a different language.
    > It's not the
    > algorithm itself but rather the language. Try coding
    > this part in a
    > different language. Even Perl will me much faster.
    > The STL is the way to
    > go these days. Try using a vector with the STL sort
    > and find algorithms
    > and you'll see it's very fast and probably meets the
    > speeds of a hash in
    > PHP.
    >
    > Don't get me wrong, I'm not bashing PHP. It's just
    > that it wasn't
    > designed for intense algorithmic purposes. The web
    > is very flexible and
    > mixing languages shouldn't be too difficult to do. I
    > know Python does
    > extending and embedding.
    >
    > Don't just look at the algorithm, look at the whole
    > picture.
    >
    Ok good advice, I think you are quite right, maybe I
    am trying to do something with a language that is not
    designed to do what I want.

    Even I am thinking in C as a cgi.

    Than you.

    ===== 

    --
Sergio Basurto J.
If I have seen further it is by standing on the 
shoulders of giants. (Isaac Newton)
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