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

Find the adjacency matrix, Consider the digraph G with three vertices P1,P2...

Consider the digraph G with three vertices P1,P2 and P3 and four directed edges, one each from P1 to P2, P1 to P3, P2 to P3 and P3 to P1. a. Sketch the digraph. b. Find the a

Dijkstra's algorithm, Q. Explain Dijkstra's algorithm for finding the short...

Q. Explain Dijkstra's algorithm for finding the shortest path in the graph given to us.  Ans: The Dijkstra's algorithm: This is a problem which is concerned with finding

Pre-order and post order traversal of a binary tree, The pre-order and post...

The pre-order and post order traversal of a Binary Tree generates the same output. The tree can have maximum One node

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

Illustrate the intervals in mathematics, Illustrate the intervals in mathem...

Illustrate the intervals in mathematics Carrier set of a Range of T is the set of all sets of values v ∈ T such that for some start value s ∈ T and end value e ∈ T, either s ≤

Define rule-based expert system, 1. Define the following terms in a rule-ba...

1. Define the following terms in a rule-based expert system? a) Knowledge base b) Inference engine 2. What is a fuzzy rule? Explain the difference between classical and fuzzy

Technique for direct search, Technique for direct search is    Hashing ...

Technique for direct search is    Hashing is the used for direct search.

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

what is frequency count with examble? examble?

Different ways for representing s graph, W h at are the different ways by...

W h at are the different ways by which we can represent graph?  Represent the graph drawn below using those ways.     T he d iff e r e nt w a y s by

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