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

Algorithms and flowcharts, write an algorithm and draw a flowchart to calcu...

write an algorithm and draw a flowchart to calculate the perimeter and area of a circle

Relationship between shortest path distances of modified, a) Given a digrap...

a) Given a digraph G = (V,E), prove that if we add a constant k to the length of every arc coming out from the root node r, the shortest path tree remains the same. Do this by usin

Arrays, Data array A has data series from 1,000,000 to 1 with step size 1, ...

Data array A has data series from 1,000,000 to 1 with step size 1, which is in perfect decreasing order. Data array B has data series from 1 to 1,000,000, which is in random order.

Program insertion of a node into any circular linked list, Program Insertio...

Program Insertion of a node into any Circular Linked List Figure depicts a Circular linked list from which an element was deleted. ALGORITHM (Deletion of an element from a

What is quick sort, What is quick sort? Quick sort is a sorting algorit...

What is quick sort? Quick sort is a sorting algorithm that uses the idea if split and conquer. This algorithm chooses an element called as pivot element; search its position in

Algorithm to count number of nodes, Write an algorithm to count number of n...

Write an algorithm to count number of nodes in the circular linked list.                            Ans. Counting No of Nodes in Circular List Let list be a circular h

Write the algorithm to find input and output value, This algorithm inputs 5...

This algorithm inputs 5 values and outputs how many input numbers were positive and how many were negative. Data to be used: N = 1, -5, 2, -8, -7

Binary search tree, write an algorithm to delete an element x from binary...

write an algorithm to delete an element x from binary search with time complex

Compare two functions, Comp are two functions n 2    and  2 n  / 4...

Comp are two functions n 2    and  2 n  / 4  for distinct values of n.   Determine When s ec on d function b ec om es l a r g er th an f i r st functi

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