How do you merge two sorted linked lists into one sorted list?
PICTURE THIS: GIT FLOW
Simple meaning
Use a dummy head and append the smaller current node from either list, then attach any leftover tail.
WHY — Linked List instead of guessing?
Why interviewers care about Linked List:
question about Linked List.
trade-offs, and what you would actually do on a DSA project - not buzzwords.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1Use a dummy head
and append the smaller current node from either list, then attach any leftover tail.
- 2Time is O(n+m) and
extra space is O(1) if you reuse nodes.
- 3Recursion is elegant but
O(n+m) stack space, which interviewers often flag.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
Use a dummy head and append the smaller current node from either list, then attach any leftover tail. Time is O(n+m) and extra space is O(1) if you reuse nodes.