MadeEasy Test Series: Algorithms - Sorting

Question

Consider a scenario of modified quick sort, where we have given an input sorted array A[1 .. . n], all elements of array are distinct and n >=3. Pivot is the median of set of 3 elements [First element, middle element, and last element]. What will be worst case time complexity of modified quick sort?

a.O($n^{2}$)
b.O(nlogn)
c.O($n^{2}$logn)
d.O(nloglogn)

Comments

It should be O(nlogn) in worst case because, selecting median as pivot means it will be always  placed at the middle after applying partition algorithm.

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B is the correct option

Because for every split occur at the middle .

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See this

https://www.geeksforgeeks.org/can-quicksort-implemented-onlogn-worst-case-time-complexity/

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what is that means[ Pivot is the median of set of 3 elements ].

Answer 1

Worst case would be Θ($n^2$) because input array given is already sorted.

Comments

No. See this:

https://www.geeksforgeeks.org/can-quicksort-implemented-onlogn-worst-case-time-complexity/

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i think O(nlogn) is right answer....

Answer 2

B should be the correct option.

Answer 3

Option B is the correct answer.

lets consider an array 1,2,3,4,5

according to the question median of an array = median(1,3,5)= 3.

so the array is divided into almost equal halves and for that time complexity would be O(nlogn)

Answer 4

option B) O(nlogn) is correct , because everytime array is divided into almost equal parts.