Answer : Median of List
Every time if we take median as the pivot element using partition algorithm it takes O(n) time .then replace the median with last element(it is a/c to your algorithm means what you have chosen as pivot here I assumed last element as pivot .) it will take O(1) constant time to replace last element with median, and every time it divides the problem into 2 half
T(n) = O(n) + T(n/2) solve using master theorem and get complexity as O(nlogn)
In the above equation O(n) is in case of Partition algorithm.