How do you merge k sorted linked lists into one sorted list?
PICTURE THIS: GIT FLOW
Simple meaning
Push the head of each list into a min-heap of (value, node) and repeatedly pop the smallest, pushing its next.
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:
- 1Push the head of
each list into a min-heap of (value, node) and repeatedly pop the smallest, pushing its next.
- 2Time is O(N log
k) for N total nodes and space is O(k).
- 3Pairwise divide-and-conquer merge is
also O(N log k) with O(log k) stack space.
- 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
Push the head of each list into a min-heap of (value, node) and repeatedly pop the smallest, pushing its next. Time is O(N log k) for N total nodes and space is O(k).