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

Data Warehousing, Assume you are in the insurance business. Find two exampl...

Assume you are in the insurance business. Find two examples of Type 2 slowly changing dimensions in that business. As an analyst on the project, write the specifications for applyi

What is Polyphase Sort, One of the best known methods for external sorting ...

One of the best known methods for external sorting on tapes is the polyphase sort. Principle: The basic strategy of this sort is to distribute ordered initial runs of predetermi

Hash table, Programming for hash table?

Programming for hash table?

Depth first search, DEPTH FIRST SEARCH (DFS) The approach adopted into ...

DEPTH FIRST SEARCH (DFS) The approach adopted into depth first search is to search deeper whenever possible. This algorithm frequently searches deeper through visiting unvisite

Representation of arrays?, A representation of an array structure is a mapp...

A representation of an array structure is a mapping of the (abstract) array with elements of type T onto the store which is an array with elements of type BYTE. The array could be

Frequency count, what is frequency count with examble? examble?

what is frequency count with examble? examble?

How can the third dimension be displayed on the screen, How can the third d...

How can the third dimension be displayed on the screen The main problem in visualization is the display of three-dimensional objects and scenes on two-dimensional screens. How

Define binary tree, Define Binary Tree  A binary tree T is explained as...

Define Binary Tree  A binary tree T is explained as a finite set of nodes that is either empty or having of root and two disjoint binary trees TL, and TR known as, respectively

..#title, whate is meant by the term heuristic

whate is meant by the term heuristic

Stack, Explain in detail the algorithmic implementation of multiple stacks....

Explain in detail the algorithmic implementation of multiple stacks.

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