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

What are expression trees, What are expression trees?  The leaves of an...

What are expression trees?  The leaves of an expression tree are operands, like as constants or variable names, and the other nodes have operators. This certain tree happens to

Determine the comparison of gouraud and phong shading, Comparison of Gourau...

Comparison of Gouraud and Phong Shading Phong shading requires more calculations, but produces better results for specular reflection than Gouraud shading in the form of more r

Define graph, A graph is a mathematical structure giving of a set of vertex...

A graph is a mathematical structure giving of a set of vertexes (v1, v2, v3) and a group of edges (e1, e2, e3). An edge is a set of vertexes. The two vertexes are named the edge en

Sparse matrix, How sparse matrix stored in the memory of a computer?

How sparse matrix stored in the memory of a computer?

Construction of a binary tree , Q. Construct a binary tree whose nodes in i...

Q. Construct a binary tree whose nodes in inorder and preorder are written as follows: Inorder : 10, 15, 17, 18, 20, 25, 30, 35, 38, 40, 50 Preorder: 20, 15, 10

Flowcharts, draw a flowchart which prints all the even numbers between 1-50...

draw a flowchart which prints all the even numbers between 1-50

What is quick sort, What is quick sort?   Answer Quick sort is on...

What is quick sort?   Answer Quick sort is one of the fastest sorting algorithm used for sorting a list. A pivot point is chosen. Remaining elements are divided or portio

Need it urgently, Write an assembly program to separate the number of posit...

Write an assembly program to separate the number of positive numbers and negative numbers from a given series of signed numbers.

Sequential files, In this section, we will discuss about Sequential file or...

In this section, we will discuss about Sequential file organization. Sequential files have data records stored in a particular sequence. A sequentially organized file might be stor

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