The flower-naming thing threw me for a second, felt like a trick.
Model the castle as a directed graph where each room is a node and each instruction is a directed edge. Then, traverse the graph to find all rooms containing treasure, handling cycles and ensuring all reachable rooms are visited.
Pro tip: Clarify with the interviewer whether the graph is guaranteed to be connected and whether there can be multiple treasure rooms. Also, discuss the trade-offs between BFS and DFS, and mention that cycle detection is crucial to avoid infinite loops.
Ask questions to understand the input format, whether the graph is directed, if there are cycles, and how treasure is indicated. Confirm if all rooms are reachable from a starting room.
Represent the castle as an adjacency list or matrix. Use a set or boolean array to track visited rooms and a list to collect treasure rooms.
Use BFS or DFS to traverse the graph from the starting room, marking visited nodes and checking for treasure. Handle cycles by not revisiting nodes.
Write pseudocode or code, then walk through examples including edge cases like cycles, disconnected components, and no treasure.
State time and space complexity: O(V+E) for traversal, O(V) for visited set and output.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.