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 for binary search, Illustrates the program for Binary Search. P...

Illustrates the program for Binary Search. Program: Binary Search /*Header Files*/ #include #include /*Functions*/ void binary_search(int array[ ], int value,

Describe commonly used asymptotic notations, Q.1 Compare two functions n 2 ...

Q.1 Compare two functions n 2 and 2 n for various values of n. Determine when second becomes larger than first. Q.2 Why do we use asymptotic notation in the study of algorit

Doubly linked lists-implementation, In any singly linked list, each of the ...

In any singly linked list, each of the elements contains a pointer to the next element. We have illustrated this before. In single linked list, traversing is probable only in one d

Define midsquare method, Midsquare Method :- this operates in 2 steps. In t...

Midsquare Method :- this operates in 2 steps. In the first step the square of the key value K is taken. In the 2nd step, the hash value is obtained by deleting digits from ends of

C++, #What is the pointer

#What is the pointer

Postorder traversal of a binary tree, Postorder traversal of a binary tree ...

Postorder traversal of a binary tree struct NODE { struct NODE *left; int value;     /* can take any data type */ struct NODE *right; }; postorder(struct NODE

Recursion, difference between recursion and iteration

difference between recursion and iteration

Structures for complete undirected graphs, Q. Draw  the structures of compl...

Q. Draw  the structures of complete  undirected  graphs  on  one,  two,  three,  four  and  five vertices also prove that the number of edges in an n vertex complete graph is n(n-1

Procedures, what is far and near procedures in system programming?

what is far and near procedures in system programming?

Relative and direct files, Each data record contains a fixed place in a rel...

Each data record contains a fixed place in a relative file. Each record ought to have associated with it in integer key value which will help identify this slot. Therefore, this ke

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