Programmatically obtaining Big-O efficiency of code

Question

I wonder whether there is any automatic way of determining (at least roughly) the Big-O time complexity of a given function?

If I graphed an O(n) function vs. an O(n

Answer 1

You must also take care when running such benchmarks. Some algorithms will have a behavior heavily dependent on the input type.

Take Quicksort for example. It is a worst-case O(n²), but usually O(nlogn). For two inputs of the same size.

The traveling salesman is (I think, not sure) O(n²) (EDIT: the correct value is 0(n!) for the brute force algotithm) , but most algorithms get rather good approximated solutions much faster.

This means that the the benchmarking structure has to most of the time be adapted on an ad hoc basis. Imagine writing something generic for the two examples mentioned. It would be very complex, probably unusable, and likely will be giving incorrect results anyway.