Merge K Sorted Lists

Heap / Priority Queue is a repeated product-company interview pattern because it tests whether you can turn a brute-force idea into a predictable invariant.

Open on LeetCode

Question

Merge K Sorted Lists: solve the core Heap / Priority Queue interview version without brute force.

Work through one tiny example by hand before writing the final logic.

Approach

Try framing your own approach first. The 30 seconds you think before peeking is where learning happens.

Clean Solution

Reveal the approach first.

How well did you understand?

Your rating tunes when this problem shows up again.

Common Mistakes

Do not start with code; first name the invariant.
Check empty input, one-element input, and duplicate values.

Next Similar Problems

Kth Largest Element in a Streameasy Find Median from Data Streamhard