We are trying to optimise the pivot selection of the Quicksort algorithm. For our pivot choice, we are using an algorithm to find the median of an unsorted list. The algorithm we opt to use for this takes O (n) time, where n is the size of the list we are partitioning. This would make the overall worst-case time complexity of Quicksort as O (nlogn) . Why don't we use this approach in general?

Question

We are trying to optimise the pivot selection of the  Quicksort  algorithm. For our pivot choice, we are using an algorithm to find the median of an unsorted list. The algorithm we opt to use for this takes O (n)  time, where  n  is the size of the list we are partitioning. This would make the overall worst-case time complexity of  Quicksort  as O (nlogn) . Why don't we use this approach in general?

Answer

There's no algorithm to calculate the median in  O(n)  time

Answer

While the linear overhead of finding the median is not visible in the asymptotic description, we assume it to be too large to be practical

Answer

We would have to sort the list before we can calculate the median

Answer

This is a better approach and we should use it

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We are trying to optimise the pivot selection of the Quicksort algorithm. For ...

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