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

Explain in brief the asymptotic notations, Question 1 Write the different ...

Question 1 Write the different characteristics of an algorithm Question 2 Explain in brief the asymptotic notations Question 3 Write an algorithm of insertion sort and e

Explain th term input and output- pseudocode, Explain th term input and ou...

Explain th term input and output-  Pseudocode Input and output indicated by the use of terms input number, print total, output total, print "result is" x and so on.

What is algorithms optimality, What is algorithm's Optimality? Optimali...

What is algorithm's Optimality? Optimality  is  about  the  complexity  of  the  problem  that  algorithm  solves.  What  is  the  minimum amount  of  effort  any  algorithm  w

Linked lists, what are grounded header linked lists?

what are grounded header linked lists?

State the ruby programming language, The Ruby Programming Language Alth...

The Ruby Programming Language Although data structures and algorithms we study aren't tied to any program or programming language, we need to write particular programs in speci

The theta-notation, This notation bounds a function to in constant factors....

This notation bounds a function to in constant factors. We say f(n) = Θ(g(n)) if there presents positive constants n 0 , c 1 and c 2 such that to the right of n 0 the value of f

Define binary search technique, Binary search technique:-  This techniq...

Binary search technique:-  This technique is applied to an ordered list where elements are arranged either in ascending order or descending order. The array is separated into t

C, padovan string

padovan string

Binary search trees, In this unit, we discussed Binary Search Trees, AVL tr...

In this unit, we discussed Binary Search Trees, AVL trees and B-trees. The outstanding feature of Binary Search Trees is that all of the elements of the left subtree of the root

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