The setup is a bit verbose but it's basically graph reachability.
Model the services and dependencies as a directed graph where an edge from A to B means A depends on B. Then perform a traversal (BFS/DFS) starting from all offline services, following reverse dependency edges to find all affected services. Include the initially stopped services in the result set.
Pro tip: Clarify the direction of dependencies upfront: if the map is service -> dependents, you can traverse forward; if it's service -> dependencies, you need to reverse the edges. Also, mention that you'll deduplicate results using a set to avoid duplicates in cyclic graphs.
Confirm the map's direction (service to dependents or dependencies), whether the stopped services are included in the output, and handle edge cases like cycles, multiple stopped services, and services with no dependents.
Represent services as nodes and dependencies as directed edges. If the map is service -> dependencies, reverse the edges to get service -> dependents for forward traversal.
Use BFS or DFS starting from all stopped services, following edges to dependents. Use a visited set to avoid revisiting nodes and handle cycles.
The visited set contains all affected services, including the initially stopped ones. Return this set as the result.
State time complexity O(V+E) and space O(V+E). Mention potential optimizations like early termination if only a subset is needed, or parallel traversal for large graphs.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.