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

Balance theorem, Question 1 Discuss the following theorems with respect to...

Question 1 Discuss the following theorems with respect to Splay Trees- Balance Theorem Dynamic Finger Theorem   Question 2 Write a C program for implementation

Darw a flowchart for inputs number of hours of sunshine, This algorithm inp...

This algorithm inputs number of hours of sunshine recorded every day for a week (7 days). Output is the highest value for hours of sunshine and average (mean) value for numbers of

Storing street addresses with doubly linked lists, Write a C++ program with...

Write a C++ program with header and source les to store street addresses using the Doubly Linked List ADT. Modify the Node class from Lab Assignment 3 so that it becomes a node in

Big o notation, This notation gives an upper bound for a function to within...

This notation gives an upper bound for a function to within a constant factor. Given Figure illustrates the plot of f(n) = O(g(n)) depend on big O notation. We write f(n) = O(g(n))

Explain about hubs, Hubs - In reality a multiport repeater - Connect...

Hubs - In reality a multiport repeater - Connects stations in a physical star topology - As well may create multiple levels of hierarchy to remove length limitation of 10

How to measure the algorithm efficiency, How to measure the algorithm's eff...

How to measure the algorithm's efficiency? It is logical to examine the algorithm's efficiency as a function of some parameter n showing the algorithm's input size. Instance

Explain best - fit method, Best - Fit Method: - This method obtains the sma...

Best - Fit Method: - This method obtains the smallest free block whose  size is greater than or equal to get such a block by traversing the whole free list follows.

Conversion of general trees into the binary trees, By taking an appropriate...

By taking an appropriate example explain how a general tree can be represented as a Binary Tree.                                                                    C onversio

State an algorithm which inputs 3 - digit code for 280 items, A small shop ...

A small shop sells 280 different items. Every item is identified by a 3 - digit code. All items which start with a zero (0) are cards, all items which start with a one (1) are swee

Properties of red- black tree, Any Binary search tree has to contain follow...

Any Binary search tree has to contain following properties to be called as a red- black tree. 1. Each node of a tree must be either red or black. 2. The root node is always b

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