O(N log N) Complexity - Similar to linear?

Posted by gav on Stack Overflow See other posts from Stack Overflow or by gav
Published on 2009-06-07T18:59:16Z Indexed on 2010/06/06 12:02 UTC
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language-agnostic

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complexity

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quicksort

Hey All,

So I think I'm going to get buried for asking such a trivial but I'm a little confused about something.

I have implemented quicksort in Java and C and I was doing some basic comparissons. The graph came out as two straight lines, with the C being 4ms faster than the Java counterpart over 100,000 random integers.

Results

The code for my tests can be found here;

android-benchmarks

I wasn't sure what an (n log n) line would look like but I didn't think it would be straight. I just wanted to check that this is the expected result and that I shouldn't try to find an error in my code.

I stuck the formula into excel and for base 10 it seems to be a straight line with a kink at the start. Is this because the difference between log(n) and log(n+1) increases linearly?

Thanks,

Gav

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