Algorithms | Sorting | Question 2

Suppose we have an O(n) time algorithm that finds the median of an unsorted array. Now consider a QuickSort implementation where we first find the median using the above algorithm, then use the median as a pivot. What will be the worst-case time complexity of this modified QuickSort?

(A)

O(n^2 Logn)

(B)

O(n^2)

(C)

O(n Logn Logn)

(D)

O(nLogn)

Answer: (D)

Explanation:

If we use the median as a pivot element, then the recurrence for all cases becomes T(n) = 2T(n/2) + O(n)

The above recurrence can be solved using Master Method. It falls in case 2 of the master method.

Quiz of this Question
Please comment below if you find anything wrong in the above post

My Personal Notes arrow_drop_up

Save