ZEAL TESTSERIES

Question

Options:

• A. 10, 12,14, 16, 18, 20
• B. 20, 18, 16, 14, 12, 10
• C. 12, 10, 16, 14, 20, 18
• D. NONE

Comments

none ?

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They marked B as right one. But I feel A should be the answer.

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Sorry my bad . correct answer is (B) .

Answer 1

So , we got the initial list and the last while loop just print the list in reverse order .

So correct answer is (B) .

https://stackoverflow.com/questions/9086372/how-to-compare-pointers#:~:text=Two%20pointers%20of%20the%20same,2).&text=%5B...%5D,are%20null%2C%20they%20compare%20equal.

 

Comments

@Kabir5454 so The reason why we got reverse list is because when the loop breaks the FRONT pointer is pointing to the element 20. That means now due to this the list will start from 20 onwards. RIght?

Please do reply if this is the reason.

If that’s the case then I overlooked the final position of pointer and so I felt the answer should have been A.

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There are 4 pointers namely ,$Head$,$Tail$ ,$Front$,$Back$ .

$Head$ points to starting node of the list .

$Tail$ points to ending node of the list .

Stating of the program $Front=Head$ , which implies $Front$ also start pointing to starting node of the list  and $Back=Tail$ , which implies $Back$ also start pointing to last node of the list.

in the program we manipulate $Front$ and $Back$ pointer but remember $Head$,$Tail$ pointer still points to starting node and ending node of the list.

After the while($Front$!=$Back$) loop breaks both $Front$ and $Back$ points to $Null$ that’s the reason the while loop terminates .

Now after that we again initialize $Back=Tail$ .[ $Tail$ still points to end of the list] .

Now the last while loop is iterating the while loop from backwards Which produce output as reverse of the list .

(I already attached each step while when the first while loop runs then what will be the output in each iteration)

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Ah! Got it. Thanks.