Heap / Priority Queuehard70 minSoftware Engineer

Tickets Real-Time Top-K Prioritizer

Name: ProdMatch.ai
Availability: InStock

Software Engineer signal: heap + top-k in a support ticket routing context. This is a ProdMatch-owned software engineer drill, framed as a March 2026 ShareChat Service Desk simulation, not a copied platform question.

Company context

ShareChat · Service Desk

Freshness

March 2026

Product surface

support ticket routing

ProdMatch interview simulation based on product-team patterns; not a claim of a real company question.

Question

Your Service Desk team needs a live top-k view for tickets. Each update changes an item's score. Return the current top k item IDs after each update, ordered by score desc then ID asc.

Input

Initial scores, k, and update stream [id, delta].

Output

Top-k IDs after every update.

Constraints

1 <= items <= 200000
1 <= updates <= 200000
Scores can be negative.

Concepts

invariants
API correctness
graph modelling
heap
top-k
streaming rank

scores: [5,1,3], k=2, update [1,+5] -> [1,0]

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

Use a stable tie-breaker for equal scores.
Do not sort the full stream when k is small.

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