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

Definitions of graph, A graph G might be defined as a finite set V of verti...

A graph G might be defined as a finite set V of vertices & a set E of edges (pair of connected vertices). The notation utilized is as follows: Graph G = (V, E) Consider the g

Explain avl tree, AVL tree An AVL tree is a binary search tree in which...

AVL tree An AVL tree is a binary search tree in which the height of the left and right subtree of the root vary by at most 1 and in which the left and right subtrees are again

Write an algorithm for binary search, Q.1 Write procedures/ Algorithm to in...

Q.1 Write procedures/ Algorithm to insert and delete an element in to array. Q.2. Write an algorithm for binary search. What are the conditions under which sequential search of

Simplifying assumptions of wire frame representation, Simplifying Assumptio...

Simplifying Assumptions of wire frame representation Neglect colour - consider Intensity: For now we shall forget about colour and restrict our discussion just to the intensi

Efficient algorithms.., implementation of fast fourier transforms for non p...

implementation of fast fourier transforms for non power of 2

Branch and bound algorithm, Suppose we have a set of N agents and a set of ...

Suppose we have a set of N agents and a set of N tasks.Each agent can only perform exactly one task and there is a cost associated with each assignment. We would like to find out a

Hash function, Q. Define the graph, adjacency matrix, adjacency list, hash ...

Q. Define the graph, adjacency matrix, adjacency list, hash function, adjacency matrix, sparse matrix, reachability matrix.

Insertion of an element in a linear array, To delete an element in the list...

To delete an element in the list at the end, we can delete it without any difficult. But, assume if we desire to delete the element at the straining or middle of the list, then, we

Surrounding of sub division method, Surrounding of sub division method ...

Surrounding of sub division method A polygon surrounds a viewport if it completely encloses or covers the viewport. This happens if none of its sides cuts any edge of the viewp

Graph terminologies, Graph terminologies : Adjacent vertices: Two vert...

Graph terminologies : Adjacent vertices: Two vertices a & b are said to be adjacent if there is an edge connecting a & b. For instance, in given Figure, vertices 5 & 4 are adj

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