Graphshard70 minFrontend Engineer

Autocomplete Dependency DAG Recovery

Frontend Engineer signal: topological sort + cycle detection in a search autocomplete context. This is a ProdMatch-owned frontend engineer drill, framed as a May 2026 BrowserStack Search UX simulation, not a copied platform question.

Company context

BrowserStack · Search UX

Freshness

May 2026

Product surface

search autocomplete

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

Question

You own search autocomplete for a Frontend Engineer loop. Given queries and directed dependencies between them, return a valid execution order. If a cycle exists, return an empty list and identify that the rollout is blocked.

Input

n nodes labelled 0..n-1 and dependency pairs [before, after].

Output

A valid order of all nodes, or [] when dependencies contain a cycle.

Constraints

1 <= n <= 200000
0 <= dependencies.length <= 400000
The graph may be disconnected.

Concepts

render scheduling
state graphs
virtualization
topological sort
cycle detection
dependency graph

queries: 4, deps: [[0,1],[0,2],[2,3]] -> [0,1,2,3] or [0,2,1,3]

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?

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Common Mistakes

Mark visited when enqueueing, not after repeated dequeue.
Do not ignore disconnected components if the product surface can have them.

Next Similar Problems

Timeline Dependency DAG Recoverymedium Timeline Evidence Path Finderhard Autocomplete Evidence Path Findermedium