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

Single pointer pointing to the tail of the queue, Can a Queue be shown by c...

Can a Queue be shown by circular linked list with only single pointer pointing to the tail of the queue? Yes a Queue can be shown by a circular linked list with only single p

Reverse order of elements on a slack, Q. Describe the representations of gr...

Q. Describe the representations of graph. Represent the graph which is given to us using any two methods Ans: The different ways by which we can represent graphs are:

Explain memory allocation strategies, Memory Allocation Strategies If i...

Memory Allocation Strategies If it is not desirable to move blocks of due storage from one area of memory to another, it must be possible to relocate memory blocks that have be

Tree traversals, There are three kinds of tree traversals, namely, Postorde...

There are three kinds of tree traversals, namely, Postorder , Preorder and Inorder. Preorder traversal: Each of nodes is visited before its children are visited; first the roo

Implementation of stack, In this unit, we have learned how the stacks are i...

In this unit, we have learned how the stacks are implemented using arrays and using liked list. Also, the advantages and disadvantages of using these two schemes were discussed. Fo

Define the term ''complexity of an algorithm, Define the term 'complexity o...

Define the term 'complexity of an algorithm; Complexity of an algorithm is the calculate of analysis of algorithm. Analyzing an algorithm means predicting the resources that th

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

What is solid modeling, What is Solid modeling Solid modeling is the mo...

What is Solid modeling Solid modeling is the most powerful of the 3-D modeling technique. It provides the user with complete information about the model. Defining an object wit

Sparse matrix, what are the disadvantages of sparse matrix?

what are the disadvantages of sparse matrix?

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