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

Number of operations possible on ordered lists and arrays, Q. Enumerate num...

Q. Enumerate number of operations possible on ordered lists and arrays.  Write procedures to insert and delete an element in to array.

Algorithams example, any simple algoritham questions with answers

any simple algoritham questions with answers

Binary search trees, In this unit, we discussed Binary Search Trees, AVL tr...

In this unit, we discussed Binary Search Trees, AVL trees and B-trees. The outstanding feature of Binary Search Trees is that all of the elements of the left subtree of the root

Queue be represented by circular linked list, Q. Can a Queue be represented...

Q. Can a Queue be represented by circular linked list with only one pointer pointing to the tail of the queue? Substantiate your answer using an example. A n s . Yes a

Shortest path algorithms, A driver takes shortest possible route to attain ...

A driver takes shortest possible route to attain destination. The problem which we will discuss here is similar to this type of finding shortest route in any specific graph. The gr

Double linked list, In a doubly linked list, also called as 2 way list, eac...

In a doubly linked list, also called as 2 way list, each node is divided into 3 parts. The first part is called previous pointer field. It contains the address of the preceding

Recursive and iterative handling of a binary search tree, This section pres...

This section prescribes additional exercise with the recursive and iterative handling of a binary search tree. Adding to the Binary Search Tree Recursively Add implementation

What is a linear array, What is a linear array? An array is a way to re...

What is a linear array? An array is a way to reference a series of memory locations using the similar name. Every memory location is shown by an array element. An  array elemen

Binary search, An unsorted array is searched through linear search that sca...

An unsorted array is searched through linear search that scans the array elements one by one until the wanted element is found. The cause for sorting an array is that we search

Algorithms, Write an algorithm to print all even numbers in descending orde...

Write an algorithm to print all even numbers in descending order and draw the flowchart

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