Improving the Quick sort

Question

If possible, how can I improve the following quick sort(performance wise). Any suggestions?

void main()
    {
      quick(a,0,n-1);
    }

    void quick(i         


        

Answer 1

The first thing to do is benchmark it. And benchmark it against the standard qsort, and against the c++ std::sort and std::stable_sort.

Your results, should your data-set be big enough, will show that the std::sort is superior to qsort in all cases except those where the std::stable_sort is superior. This is because the std::sort is templated, and therefore the comparision can be inlined.

Your code inlines the comparison because its not generic. If your code is slower than qsort, you have a problem right there.

The faster sort would be to sort parts in parallel, e.g. openmp, and then merge them back together.