Graphsmedium45 minSecurity Engineer

Attack Dependency DAG Recovery

Security Engineer signal: topological sort + cycle detection in a attack path analysis context. This is a ProdMatch-owned security engineer drill, framed as a March 2026 Ola Cloud Security simulation, not a copied platform question.

Company context

Ola · Cloud Security

Freshness

March 2026

Product surface

attack path analysis

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

Question

You own attack path analysis for a Security Engineer loop. Given assets 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

attack graphs
policy tries
anomaly detection
topological sort
cycle detection
dependency graph

assets: 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?

Your rating tunes when this problem shows up again.

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

Attack Evidence Path Finderhard Policy Dependency DAG Recoveryhard Policy Evidence Path Findermedium