Complexity of an algorithm, Data Structure & Algorithms

Assignment Help:

Q. Explain the complexity of an algorithm?  What are the worst case analysis and best case analysis explain with an example.                                                                                                                

Ans:

The complexity of the algorithm M is the function f(n) which gives the running time or storage space requirement of the algorithm in terms of the size n of the input data. Frequently, the storage space needed by an algorithm is just a multiple of the data size n. Therefore, the term "complexity" should be referring to the running time of the algorithm.

We find the complexity function f(n) for the certain number of cases. The two cases to which one usually investigates in complexity theory are as follows:-
i. The worst case:-  the maximum value of f(n) for any input possible
ii. The best case:-  the least possible value of f(n)

For example:-

Hear if we take an example of linear search in which an integer Item is to searched or found in an array Data. The complexity if the search algorithm is given by number C of comparisons between Item and Data[k].

Worst case:-

The worst case occurs when the Item is last element in the array Data or is it not there at all. In both of these cases, we get

C(n)=n

In the average case, we presume that the Item is present is the array and is likely to be present in any position in the array. Hence the number of comparisons can be any of the numbers 1, 2, 3........n and each number occurs with probability

p = 1/n.

C(n) = 1. 1/n + 2.1/n + ... + n.1/n

= (n+1) / 2

hence the average number of comparisons needed to locate the Item in to array Data is approximately the same to half the number of elements in the Data list.


Related Discussions:- Complexity of an algorithm

Queue, what''s queue ?

what''s queue ?

Demonstrate that dijkstra''s algorithm, Demonstrate that Dijkstra's algorit...

Demonstrate that Dijkstra's algorithm does not necessarily work if some of the costs are negative by finding a digraph with negative costs (but no negative cost dicircuits) for whi

Operation of algorithm, Operation of Algorithm The following sequence o...

Operation of Algorithm The following sequence of diagrams shows the operation of Dijkstra's Algorithm. The bold vertices show the vertex to which shortest path has been find ou

Implementation of dequeue, Dequeue (a double ended queue) is an abstract da...

Dequeue (a double ended queue) is an abstract data type alike to queue, where insertion and deletion of elements are allowed at both of the ends. Like a linear queue & a circular q

Explain the abstract data type assertions, Explain the Abstract data type a...

Explain the Abstract data type assertions Generally, ADT assertions translate into assertions about the data types which implement ADTs, which helps insure that our ADT impleme

Explain multidimensional array, Multidimensional array: Multidimensional a...

Multidimensional array: Multidimensional arrays can be defined as "arrays of arrays". For example, a bidimensional array can be imagined as a bidimensional table made of elements,

Algorithm, algorithm to search a node in linked list

algorithm to search a node in linked list

Design the system for seller, Your program should include three components ...

Your program should include three components selling, buying and managing for the use of sellers, buyers and the Manager, respectively. Provide a menu for a user to enter each comp

Collision resolution techniques, complete information about collision resol...

complete information about collision resolution techniques

Recursion, difference between recursion and iteration

difference between recursion and iteration

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