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

State phong shading, Phong Shading Phong shading too is based on interp...

Phong Shading Phong shading too is based on interpolation, but instead of interpolating the colour value, it is the normal vector, which is interpolated for each point and a co

Algorithm to evaluate expression given in postfix notation , Q. Write down ...

Q. Write down an algorithm to evaluate an expression given to you in postfix notation. Show the execution of your algorithm for the following given expression. AB^CD-EF/GH+/+*

Define abstract data type & column major ordering for arrays, Q1. Define th...

Q1. Define the following terms: (i) Abstract data type. (ii) Column major ordering for arrays. (iii)  Row major ordering for arrays. Q2. Explain the following: (i) A

Array implementation of a queue, Since the stack is list of elements, the q...

Since the stack is list of elements, the queue is also a list of elements. The stack & the queue differ just in the position where the elements may be added or deleted. Similar to

Define different types of sparse matrix, Q1. Define a sparse matrix. Explai...

Q1. Define a sparse matrix. Explain different types of sparse matrices? Evaluate the method to calculate address of any element a jk of a matrix stored in memory. Q2. A linear

Compound interest, Write the algorithm for compound interest

Write the algorithm for compound interest

Deletion of an element from the linked list, A LGORITHM (Deletion of an ele...

A LGORITHM (Deletion of an element from the linked list) Step 1  Begin Step 2  if the list is empty, then element cannot be deleted Step 3  else, if the element to be del

Data communication, #question.explain different types of errors in data tra...

#question.explain different types of errors in data transmission.

Define merge sort, Define Merge Sort  Merge sort is a perfect example ...

Define Merge Sort  Merge sort is a perfect example of a successful application of the divide and conquer method. It sorts a given array A[0...n-l] by separating it into two ha

Accept a file and form a binary tree - huffman encoding, Huffman Encoding i...

Huffman Encoding is one of the very simple algorithms to compress data. Even though it is very old and simple , it is still widely used (eg : in few stages of JPEG, MPEG etc). In t

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