The Gateway to Computer Science Excellence
+1 vote

The Answer given is A) 

I think the naswer should be B) as we have both the prev pointer and the next pointer available , it will take constant time to update the adjacent nodes pointers and delete the given node .?

in DS by Active (4.5k points) | 900 views
In linked list finding element itself takes O(n) time and deletion takes O(1) time,so it is O(n).

suppose if elements stored in DLL are (head)12,5,8,6,9,4,13(tail).

to find an element '9' worst case we need to traverse entire list.

So does deletion include search time as well ? 

I thought that the position of the node is already known and we have to only perform deletion.

So if this question comes in exam what do we consider ?


For deletion=search time+link modification

When deleted node address is given then in CDLL we can perform deletion in O(1) time.

In SLL eventhough deleted node address given it takes O(n) time.

In the given question address is not specified so TC=O(n) otherwise it is O(1) only in CDLL but not DLL.

IN DLL also reaching last node it takes O(n) time in CLL with help of prev pointer at first node we can reach last in O(1)

1 Answer

+4 votes
Best answer

If the pointer to the node to be deleted is given then worst case time complexity would be O(1). But since it is not given, we would have only pointer to the head. So before deleting we would have to search by traversing the LL. In worst case it might take O(n) and deleting would take only O(1). 

Thus O(n).

by Active (1.5k points)
selected by

Related questions

Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true
50,737 questions
57,306 answers
105,012 users