ISRO2017-16

Question

Given two statements

1. Insertion of an element should be done at the last node of the circular list
2. Deletion of an element should be done at the last node of the circular list

• A. Both are true
• B. Both are false
• C. First is false and second is true
• D. None of the above

Comments

I think ans should be both are false as there is no such start or end node in a circular list.

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What is the meaning of second statement?

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Sir its mistake in writing. Its 'an' not 'n'

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@Arjun Sir you agree both are false? My thought is since in a circular list there is no such as start or end node

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yes, you are correct but since it is ISRO exam I have no guarantee for the official key :)

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In circular linked list a tail pointer is maintained that contains the address of the node before the head node.This pointer is maintained for insertion and deletion without traversing the whole list so

insertion can be done at the end of list using tail pointer

and deletion can be done at beginning using tail pointer

so i think first is true and 2nd is false so none .

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@Arjun sir,@Bikram Sir

Pls Verify this qus answer given by ISRO is D ?

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@ManojK and @Kapil

yes B is correct option, 

1. Insertion of an element should be done at the last node of the circular list = = True , it can be possible at last node .

http://scanftree.com/Data_Structure/insertion-in-circular-linked-list

1. Deletion of an element should be done at the last node of the circular list = = True , it can also be possible at last node

http://scanftree.com/Data_Structure/Deletion-in-circular-linked-list

now coming to the question it says - should be done ,  it makes both options false .

If they don't mention should be , then both statements are correct as you check from those given links 

hence option B is only correct among options .

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@Bikram Sir, 

Any such rule does not exists. 

In queue, we have rules to insert from rear and delete from front.

But, not in CLL and moreover, in memory it has no predefined head or tail node. Also, what is the start and end of CLL in context of memory .

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I think if the question would have been maintaining O(1) complexity, then it makes some sense .

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Also, options say $$should\ be$$ done .

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Even, though you are also saying 

yes D is correct option, both statements are false here 

Both statements are false here :)

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@Kapil They messed up while copying the options :)

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@Arjun Sir

Now, I'm messed up thinking how many questions am i suppose to object.

The mail will be so big with explainations and they will not even bother reading it :) :P

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Still it is far better than last year :)

only 4 questions this time rt? Last year it was > 10 ..

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@kapil

Yes here both statements are correct only when they don't mention the word " should be " in question.

Just they ask those 2 operations should be done at respective positions make both statements false, 

1. Insertion of an element should be done at the last node of the circular list = = True , it can be possible at last node .

http://scanftree.com/Data_Structure/insertion-in-circular-linked-list

1. Deletion of an element should be done at the last node of the circular list = = True , it can also be possible at last node

http://scanftree.com/Data_Structure/Deletion-in-circular-linked-list

That makes B is correct option . 

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I am not getting the intention behind this question. I doubt if it contain some sense or not.

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@Rupendra

Yes, options are no sense , not have proper meaning.

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Can anyone number me the questions with wrong answer key from isro.

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@chahat bahl

There are 3 questions should be challenged ,

one is digital question - synchronous vs asynchronous which one is faster . With wrong options are given in question itself.

second is this question - with wrong option is correct in ISRO key.

third is ISRO-2017-53 question in GO 

https://gateoverflow.in/128485/isro2017-53

thse 3 only as i can remember ..

@kapil am i missing something ?

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@Bikram Sir, Correct and that semaphore question also.

Both B and D are correct.

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Thank you sir @bikram

Answer 1

I think ans should be (b)

Comments

how?

Answer 2

Answer is D

There is no such rule in Circular Linked list