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

Deletion of an element from the linked list, A LGORITHM (Deletion of an ele...

A LGORITHM (Deletion of an element from the linked list) Step 1  Begin Step 2  if the list is empty, then element cannot be deleted Step 3  else, if the element to be del

space, What is Space complexity of an algorithm? Explain

What is Space complexity of an algorithm? Explain.

Binary search, In a sorted list, Binary search is carried out by dividing t...

In a sorted list, Binary search is carried out by dividing the list into two parts depends on the comparison of the key. Since the search interval halves each time, the iteration o

Infix expression into the postfix expression, Q. Write down an algorithm to...

Q. Write down an algorithm to convert an infix expression into the postfix expression.     Ans. Algo rithm to convert infix expression to post fix expression is given as

Array implementation of a multiqueue, Program gives the program segment by ...

Program gives the program segment by using arrays for the insertion of an element to a queue into the multiqueue. Program: Program segment for the insertion of any element to t

Explain insertion sort, Q. Explain the insertion sort with a proper algorit...

Q. Explain the insertion sort with a proper algorithm. What is the complication of insertion sort in the worst case?

Tree, tree is graph or not

tree is graph or not

Define spanning tree, Define Spanning Tree A Spanning Tree of a connect...

Define Spanning Tree A Spanning Tree of a connected graph is its linked acyclic sub graph (i.e., a tree) that having all the vertices of the graph.

Insert an element after an element pointed by some pointer, Consider a link...

Consider a linked list of n elements. What is the time taken to insert an element after an element pointed by some pointer? O (1)

A tree having ''m'' nodes has (m-1) branches. prove., Q. Prove the hypothes...

Q. Prove the hypothesis that "A tree having 'm' nodes has exactly (m-1) branches".      Ans: A tree having m number of nodes has exactly (m-1) branches Proof: A root

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