Complexity of quick sort, Data Structure & Algorithms

Assignment Help:

Q. What do you mean by the best case complexity of quick sort and outline why it is so. How would its worst case behaviour arise?                                                                                                 

Ans:

In the best case complexity, pivot is in the middle. To simplify the calculation, we assume that the two sub-files are both  exactly half  of the size of the original file, and although this gives a minor overestimate, this is except able because we are only interested in a Big-Oh answer.

T(n) = 2T(n/2) + cn

which yields

T(n) = cn log n + n = O(n log n)

In the worst case the pivot is the smallest element, all the time. Then i = 0 and if we ignore  T(0) = 1, which is not important, the recurrence is T(n) = T(n - 1) + cn, n > 1 which yields

1908_Quick Sort1.png


Related Discussions:- Complexity of quick sort

Splaying algorithm, Insertion & deletion of target key requires splaying of...

Insertion & deletion of target key requires splaying of the tree. In case of insertion, the tree is splayed to find the target. If, target key is found out, then we have a duplicat

Algorithms, write short note on algorithms

write short note on algorithms

Search engines - applications of linear and binary search, Search engines e...

Search engines employ software robots to survey the Web & build their databases. Web documents retrieved & indexed through keywords. While you enter a query at search engine websit

Process of channel access, Channel access In first generation systems, ...

Channel access In first generation systems, every cell supports a number of channels. At any given time a channel is allocated to only one user. Second generation systems also

Acyclic graphs, Acyclic Graphs In a directed graph a path is said to fo...

Acyclic Graphs In a directed graph a path is said to form a cycle is there exists a path (A,B,C,.....P) such that A = P. A graph is called acyclic graph if there is no cycle in

Objectives of lists, After going through this unit, you will be able to: ...

After going through this unit, you will be able to: • define and declare Lists; • understand the terminology of Singly linked lists; • understand the terminology of Doubly

Avl tree rotations, AVL trees and the nodes it contains must meet strict ba...

AVL trees and the nodes it contains must meet strict balance requirements to maintain O(log n) search time. These balance restrictions are kept maintained via various rotation func

Programs, Develop a program that accepts the car registration( hint: LEA 43...

Develop a program that accepts the car registration( hint: LEA 43242010)

Project, human resource management project work in c++

human resource management project work in c++

Explain best - fit method, Best - Fit Method: - This method obtains the sma...

Best - Fit Method: - This method obtains the smallest free block whose  size is greater than or equal to get such a block by traversing the whole free list follows.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd