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

Program insertion of a node into any circular linked list, Program Insertio...

Program Insertion of a node into any Circular Linked List Figure depicts a Circular linked list from which an element was deleted. ALGORITHM (Deletion of an element from a

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

Implementation of stack, In this unit, we have learned how the stacks are i...

In this unit, we have learned how the stacks are implemented using arrays and using liked list. Also, the advantages and disadvantages of using these two schemes were discussed. Fo

Types of tree ?, Binary: Each node has one, zero, or two children. This ...

Binary: Each node has one, zero, or two children. This assertion creates many tree operations efficient and simple. Binary Search : A binary tree where each and every left

Write a program to create a hashed file, Write a program to create a hashed...

Write a program to create a hashed file that stores the records currently in the file " data_2013 ". Records should use the same fixed-length schema given previously, and should ag

Explain the scan-line algorithm, Explain the Scan-Line Algorithm This i...

Explain the Scan-Line Algorithm This image-space method for removing hidden surfaces is an extension of the scan-line algorithm for filling polygon interiors. Instead of fillin

Sort wars - sorting algorithm, If quicksort is so quick, why bother with an...

If quicksort is so quick, why bother with anything else? If bubble sort is so bad, why even mention it? For that matter, why are there so many sorting algorithms? Your mission (sho

Stack making use of the linked list, Q. Implement a stack making use of the...

Q. Implement a stack making use of the linked list. Show the PUSH and POP operations both. A n s . Stack implemantation using linked list # include # include

Binary search tree, A binary search tree (BST), which may sometimes also be...

A binary search tree (BST), which may sometimes also be named a sorted or ordered binary tree, is an edge based binary tree data structure which has the following functionalities:

Doubly linked list, How does operations like insertion, deletion occur?

How does operations like insertion, deletion occur?

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