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 type, Data type An implementation of an abstract data type on a...

Data type An implementation of an abstract data type on a computer. Therefore, for instance, Boolean ADT is implemented as the Boolean type in Java, and bool type in C++;

Mapping constain, one to many one to one many to many many to one

one to many one to one many to many many to one

Determine in brief the painter algorithm, Determine in brief the Painter A...

Determine in brief the Painter Algorithm a) The farthest polygon, namely the rectangle PQRS, is stored first. (b) The next farthest, the quadrilateral ABCD, is superpo

Non-recursive implementation of preorder traversal, For preorder traversal,...

For preorder traversal, in the worst case, the stack will rise to size n/2, where n refer to number of nodes in the tree. Another method of traversing binary tree non-recursively t

Queues, what is queues? how it work? and why it used? i want an assignment...

what is queues? how it work? and why it used? i want an assignment on queue .....

Program on radix sort., Write a program that uses the radix sort to sort 10...

Write a program that uses the radix sort to sort 1000 random digits. Print the data before and after the sort. Each sort bucket should be a linked list. At the end of the sort, the

Explain the bubble sort algorithm, Explain the bubble sort algorithm. ...

Explain the bubble sort algorithm. Answer This algorithm is used for sorting a list. It makes use of a temporary variable for swapping. It compares two numbers at an insta

Importance of game theory to decisions, Question: (a) Discuss the impor...

Question: (a) Discuss the importance of game theory to decisions. (b) Explain the following: (i) saddle point, (ii) two-person zero-sum game. (c) Two leading ?rms, ABC Ltd a

Order of efficiency - linear search, Linear search employee an exhaustive m...

Linear search employee an exhaustive method of verified each element in the array against a key value. Whereas a match is found, the search halts. Will sorting the array before uti

Notes, Ask question #Minimum 10000 words accepted#

Ask question #Minimum 10000 words accepted#

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