Moderate Linked List Question 103 of 224

How do you check whether a linked list is a palindrome?

DSA interview set · Speak this in 60–90 seconds · Faridabad & Delhi NCR

01234

Index starts at 0. Scan once for max — O(n).

Find the middle with slow/fast, reverse the second half, compare pairwise, then optionally restore.

Why interviewers care about Linked List:

This is a process

question about Linked List.

Panels listen for order,

trade-offs, and what you would actually do on a DSA project - not buzzwords.

Stay structured

Name the idea, why it exists, then one short example.

Close cleanly

End with when you use it and one common pitfall.

Before you speak the answer, walk the interviewer through these steps:

1
Find the middle with
slow/fast, reverse the second half, compare pairwise, then optionally restore.
2
Time is O(n) and
extra space is O(1).
3
Copying values into an
array is O(n) space and easier if mutation is forbidden.
4
Give an example
One tiny concrete case you can say aloud.
5
Common mistake
What juniors usually get wrong.
6
Close
When you pick this over the alternative.

Here's a short line you can speak, broken into clear beats:

Say this line

“Time is O(n) and extra space is O(1).”

Break into beats

TimeisOnandextra

Speaking order

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Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.

Find the middle with slow/fast, reverse the second half, compare pairwise, then optionally restore. Time is O(n) and extra space is O(1).