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

Process of post-order traversal, Post-order Traversal This can be done ...

Post-order Traversal This can be done both iteratively and recursively. The iterative solution would need a change of the in-order traversal algorithm.

Avl tree, Example: (Single rotation into AVL tree, while a new node is inse...

Example: (Single rotation into AVL tree, while a new node is inserted into the AVL tree (LL Rotation)) Figure: LL Rotation The rectangles marked A, B & C are trees

Circular queue, explain implementation of circular queue insert,delete oper...

explain implementation of circular queue insert,delete operations

Determine the term - loops, Loops There are 3 common ways of performin...

Loops There are 3 common ways of performing a looping function: for ... to ... next, while ... endwhile and repeat ... until The below example input 100 numbers and find

Sorting, explain quick sort algorithm

explain quick sort algorithm

Stack, Explain in detail the algorithmic implementation of multiple stacks....

Explain in detail the algorithmic implementation of multiple stacks.

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

Explain the sum of subset problem, a. Explain the sum of subset problem. Ap...

a. Explain the sum of subset problem. Apply backtracking to solve the following instance of sum of subset problem: w= (3, 4, 5, 6} and d = 13. Briefly define the method using a sta

Splay trees, Addition of new records in a Binary tree structure always occu...

Addition of new records in a Binary tree structure always occurs as leaf nodes, which are further away from the root node making their access slower. If this new record is to be ac

Whether a binary tree is a binary search tree or not, Write an algorithm to...

Write an algorithm to test whether a Binary Tree is a Binary Search Tree. The algorithm to test whether a Binary tree is as Binary Search tree is as follows: bstree(*tree) {

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