Comparison between timsort and quicksort

Question

Why is it that I mostly hear about Quicksort being the fastest overall sorting algorithm when Timsort (according to wikipedia) seems to perform much better? Google didn\'t s

Answer 1

Tim Sort is great if you need an order-preserving sort, or if you are sorting a complex array (comparing heap-based objects) rather than a primitive array. As mentioned by others, quicksort benefits significantly from the locality of data and processor caching for primitive arrays.

The fact that the worst case of quicksort is O(n^2) was raised. Fortunately, you can achieve O(n log n) time worst-case with quicksort. The quicksort worst-case occurs when the pivot point is either the smallest or largest value such as when the pivot is the first or last element of an already sorted array.

We can achieve O(n log n) worst-case quicksort by setting the pivot at the median value. Since finding the median value can be done in linear time O(n). Since O(n) + O(n log n) = O(n log n), that becomes the worst-case time complexity.

In practice, however, most implementations find that a random pivot is sufficient so do not search for the median value.