The base system being pre-built was a small relief, but I spent too long re-reading the existing API instead of just jumping into the collision logic.
Start by clarifying the existing rover controller's architecture and how moves are currently executed, then propose a minimal change that checks the target cell before moving. Emphasize that the check should be atomic and that the caller must receive a clear failure notification without altering the rover's state.
Pro tip: Mention that you'd add a unit test for the collision case and consider concurrency if multiple commands can be issued simultaneously, showing you think about edge cases and reliability.
Ask clarifying questions about how rovers are stored, how moves are validated, and how errors are currently reported. Identify the exact point where a move command is executed.
Propose checking the target cell for occupancy before executing the move. Ensure the check is done atomically to avoid race conditions if the system is concurrent.
Decide on a clear error signaling mechanism (e.g., return an error code, throw an exception, or use a callback) that fits the existing API. Ensure the rover's state remains unchanged on failure.
Outline the code change, emphasizing minimal impact on existing functionality. Describe how you would test the new behavior, including edge cases like moving into an empty cell or the boundary of the grid.
Discuss potential trade-offs (e.g., performance vs. simplicity) and whether the solution can be extended to other collision types or multi-step moves.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.