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

Branch and bound algorithm, Suppose we have a set of N agents and a set of ...

Suppose we have a set of N agents and a set of N tasks.Each agent can only perform exactly one task and there is a cost associated with each assignment. We would like to find out a

Bst created in pre- order, Q. Make a BST for the given sequence of numbe...

Q. Make a BST for the given sequence of numbers. 45,32,90,34,68,72,15,24,30,66,11,50,10 Traverse the BST formed in  Pre- order, Inorder and Postorder.

Program, insertion and deletion in a tree

insertion and deletion in a tree

Abstract Data Types, A useful tool which is used for specifying the logical...

A useful tool which is used for specifying the logical properties of a data type is called the abstract data type or ADT. The term "abstract data type" refers to the fundamental ma

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

Chaining Method as Method of Collision Resolution , Q. The given values are...

Q. The given values are to be stored in a hash table 25, 42, 96, 101, 102, 162, 197 Explain how the values are hashed by using division technique of hashing with a table

Implementation of circular queues, One of the main problems with the linear...

One of the main problems with the linear queue is the lack of appropriate utilization of space. Assume that the queue can store 100 elements & the complete queue is full. Thus, it

Unification algorithm, i want to write code for unification algorithm with ...

i want to write code for unification algorithm with for pattern matching between two expression with out representing an expression as alist

Complexity, Complexity : How do the resource needs of a program or algorith...

Complexity : How do the resource needs of a program or algorithm scale (the growth of resource requirements as a function of input). In other words, what happens with the performan

What is a height balanced tree, What is a height balanced tree? Height Ba...

What is a height balanced tree? Height Balanced Tree (AVL Tree) An AVL tree is a binary search tree in which the height of the left and right subtree of the root vary by at most

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