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

Depth-first search (dfs) , In this respect depth-first search (DFS) is the...

In this respect depth-first search (DFS) is the exact reverse process: whenever it sends a new node, it immediately continues to extend from it. It sends back to previously explore

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

Program of implementation of stack using arrays, include int choice, st...

include int choice, stack[10], top, element; void menu(); void push(); void pop(); void showelements(); void main() { choice=element=1; top=0; menu()

Define minimum spanning tree, Define Minimum Spanning Tree A minimum sp...

Define Minimum Spanning Tree A minimum spanning tree of a weighted linked graph is its spanning tree of the smallest weight, where the weight of a tree is explained as the sum

Algorithm, give me algorithm of simple interest

give me algorithm of simple interest

Splay trees, Addition of new records in a Binary tree structure always occu...

Addition of new records in a Binary tree structure always occurs as leaf nodes, which are further away from the root node making their access slower. If this new record is to be ac

Algorithm, algorithm to search a node in linked list

algorithm to search a node in linked list

Calculate the k-th power and recursive algorithem, 1. The following is a r...

1. The following is a recursive algorithm to calculate the k -th power of 2. Input k a natural number Output kth power of 2 Algorithem: If k =0then return 1 Else return 2* po

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