OpenAI Online Assessment: Network Endpoint

OpenAI Online Assessment 2026

You are given a directed graph where each node has at most one outgoing edge. from_ids[i] → to_ids[i] is an edge. Node ids are integers between 1 and 5000, not necessarily ordered or consecutive, and no node links to itself.

Starting from node start, follow the edges and return:

• the last node reached, if the path ends at a node with no outgoing edge, or
• the last node visited before the path closes a loop, if it enters a cycle.