Easy Linked List Question 39 of 224

How do you find the nth node from the end of a linked list?

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

Without indexScan every row

With indexJump to keys

CostWrites slower

Advance a fast pointer n steps, then move fast and slow together until fast falls off

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
Advance a fast pointer
n steps, then move fast and slow together until fast falls off
2
Why it exists
slow lands on the nth-from-end.
3
One O(n) pass and
O(1) space.
4
Two-pass length-then-index also works
and is simpler if n might exceed the length, which you must validate.
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

“One O(n) pass and O(1) space.”

Break into beats

OneOnpassandO

Speaking order

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

Advance a fast pointer n steps, then move fast and slow together until fast falls off slow lands on the nth-from-end.