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From: Rick <rickduley@gmail.com>
Subject: Re: Inefficient algorithms
Date: Sat, 11 Sep 2010 02:07:24 -0700 (PDT)
Date: 2010-09-11T02:07:24-07:00	[thread overview]
Message-ID: <0ce6d303-c8ff-4688-8372-00238f52d1d4@s24g2000pri.googlegroups.com> (raw)
In-Reply-To: 8f0o4uFct8U1@mid.individual.net

On Sep 11, 3:07 pm, Niklas Holsti <niklas.hol...@tidorum.invalid>
wrote:
> Niklas Holsti wrote:
> > Rick wrote:
> >> I am working on a class in algorithmic efficiency and, to make a
> >> point, need an algorithm that runs O(2^n) - a factoring algorithm
> >> perhaps.  All I can find is 'C' code I can't decipher.  Can someone
> >> please help with an Ada example.
>
> > Perhaps the canonical example is this: you are given a Boolean formula
> > containing n Boolean variables. Find a valuation (a value, True or
> > False, for each variable) that makes the formula True.
>
> Replying to myself, since I realize that I probably misunderstood your
> need: what you want is an inefficient O(2^n) solution to an easy
> (non-exponential) problem. The problem I suggested is not, of course, an
> easy one. But it has easy variants. For example, require that the
> Boolean formula uses at most 10 of the n variables, where this limit
> (10) is considered a fixed number independent of the total number (n) of
> variables.
>
> --
> Niklas Holsti
> Tidorum Ltd
> niklas holsti tidorum fi
>        .      @       .

I must be a bit daft, Niklas, but I don't get it.
What sort of a Boolean formula are you talking about?  How do I use it
in a recursive function?

You help is appreciated.
Thanks



  reply	other threads:[~2010-09-11  9:07 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-11  4:24 Inefficient algorithms Rick
2010-09-11  6:51 ` J-P. Rosen
2010-09-13  3:45   ` Robert A Duff
2010-09-11  6:54 ` Niklas Holsti
2010-09-11  7:07   ` Niklas Holsti
2010-09-11  9:07     ` Rick [this message]
2010-09-11 15:05       ` Niklas Holsti
2010-09-17  5:26         ` Rick
2010-09-11  9:20     ` Ludovic Brenta
2010-09-11  9:23       ` Ludovic Brenta
2010-09-11 11:20       ` Niklas Holsti
2010-09-11 18:29         ` Peter C. Chapin
2010-09-11 14:28 ` stefan-lucks
2010-09-12  1:04   ` Wilson
2010-09-12  1:53   ` Rick
2010-09-12  8:35     ` Georg Bauhaus
2010-09-12 11:56     ` stefan-lucks
2010-09-15  1:11 ` BrianG
  -- strict thread matches above, loose matches on Subject: below --
2010-09-15  8:51 Rick
2010-09-15 21:45 ` John B. Matthews
2010-09-16 12:05   ` Chad  R. Meiners
2010-09-16 20:19     ` John B. Matthews
2010-09-17  5:24   ` Rick
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