efficiency

This is a discussion on efficiency within the Tech Board forums, part of the Community Boards category; i know this is no c++ question, can any one tel me: in efficiency class is log2^n the same and ...

  1. #1
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    efficiency

    i know this is no c++ question, can any one tel me:
    in efficiency class is log2^n the same and log3^n or logx^n, because we can change base right?

    thanks in advance .

  2. #2
    Master Apprentice phantomotap's Avatar
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    O_o

    Are you talking about "BigO"?

    If so, yes, because constant factors are abstracted away because they don't affect growth potential.

    (Unless you are taking about trying to make a O(logN(N)) algorithm look like something it probably isn't.)

    Soma

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    (?<!re)tired Mario F.'s Avatar
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    ... and why it's not even usually spelled as O(logn^n), but simply O(log n)
    Last edited by Mario F.; 06-14-2011 at 03:15 PM.
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    Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.

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    log[a](N)=log[b](N)/log(a).

    So if you have a bunch of functions that have a log term of any base, you can convert them to functions of a log term of your favorite base, with a constant product. Constant products are ignored in O(N) notation, so it doesn't matter what base is used; they are all comparable, as long as it is greater than 1.
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