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

Programs, Develop a program that accepts the car registration( hint: LEA 43...

Develop a program that accepts the car registration( hint: LEA 43242010)

State in detail about the integer, State in detail about the Integer ...

State in detail about the Integer Carrier set of the Integer ADT is the set {..., -2, -1, 0, 1, 2, ...}, and  operations on these values are addition, multiplication, subtrac

Recursion, i need help in java recursion assignment.

i need help in java recursion assignment.

Explain the question, Merging 4 sorted files having 50, 10, 25 and 15 recor...

Merging 4 sorted files having 50, 10, 25 and 15 records will take time

State z-buffer algorithm, Z-Buffer Algorithm Also known as the Depth-Bu...

Z-Buffer Algorithm Also known as the Depth-Buffer algorithm, this image-space method simply selects for  display the polygon or portion of a polygon that is nearest to the view

Perform breadth -first search, You are given two jugs, a 4-gallon one and a...

You are given two jugs, a 4-gallon one and a 3-gallon one. Neither has any measuring marker on it. There is a tap that can be used to fill the jugs with water. How can you get exac

Tree traversals, There are three kinds of tree traversals, namely, Postorde...

There are three kinds of tree traversals, namely, Postorder , Preorder and Inorder. Preorder traversal: Each of nodes is visited before its children are visited; first the roo

Algorithm of decorated graph, As we talked in class, a program with two int...

As we talked in class, a program with two integer variables is universal. Now, we consider a special form of four variableprograms. Let G = (V; E) be a directed graph, where V is a

Merging, merging 4 sorted files containing 50 10 25 and 15 records will tak...

merging 4 sorted files containing 50 10 25 and 15 records will take time

Hashing, explain collision resloving techniques in hasing

explain collision resloving techniques in hasing

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