Start by clarifying requirements and edge cases, then outline a clean object-oriented design with a Rover class and a command parser. Implement the core logic using a direction array and modular arithmetic, and finally discuss testing and potential extensions.
Pro tip: Demonstrate test-driven development by writing unit tests for each command and edge case before coding, and mention how you would handle invalid input gracefully.
Ask about input format, expected output, handling of invalid commands, and whether the rover can move off the plateau (if any).
Outline a Rover class with position (x, y) and direction, and a command processor that iterates over commands. Use an array of directions and modulo arithmetic for turns.
Write methods for turning left/right and moving forward based on current direction. Ensure movement updates coordinates correctly.
Consider invalid commands, boundary conditions (if plateau defined), and ensure the rover reports after each command.
Write unit tests for various command sequences. Discuss potential extensions like multiple rovers or obstacles.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
Start by clarifying requirements and constraints, then propose a design that separates rover state management from command execution. Walk through the command flow, including validation and error handling for invalid operations, and discuss trade-offs between different approaches.
Pro tip: Demonstrate foresight by discussing how your design would scale to hundreds of rovers and how you would test edge cases like concurrent commands or invalid selections.
Ask questions to understand the expected scale, persistence needs, and whether commands are processed synchronously or asynchronously. Confirm the exact behavior for invalid operations.
Define a Rover class/struct with position and orientation, and a RoverManager that maintains a collection of rovers and tracks the active rover ID. Consider using a map for efficient lookup.
Implement CREATE to add a new rover and optionally set it active, DELETE to remove a rover and handle active rover reassignment, SELECT to change active rover with validation, and movement commands that operate only on the active rover.
Specify error responses for selecting a non-existent rover, deleting the active rover, or issuing movement commands when no rover is active. Decide whether to throw exceptions, return error codes, or log warnings.
Talk about trade-offs between simplicity and extensibility, such as using a simple map vs. a more complex state machine. Mention potential extensions like undo/redo, persistence, or multi-user support.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
The tricky part is that 'report state after each command' now has two flavors: success and failure.
Start by clarifying the requirements: what 'fails silently' means (no exception, no error message), and that state is still reported after the failed command. Then propose a design where each move checks the destination cell for occupancy before committing, and if occupied, the move is skipped but the rover's state (position, direction) is returned. Discuss trade-offs such as atomicity, concurrency, and whether to log the failure.
Pro tip: Emphasize that 'fails silently' doesn't mean ignoring the failure—it means not disrupting the caller, but you should still consider logging or metrics for observability. Also, mention that collision avoidance should be centralized (e.g., in a grid manager) to avoid race conditions.
Ask questions to understand what 'fails silently' entails, whether multiple rovers can move concurrently, and what state needs to be reported. Confirm that the rover should not move and no error should be thrown.
Propose a mechanism to check if the destination cell is occupied, such as a grid data structure that tracks rover positions. Ensure the check is atomic to avoid race conditions.
If the destination is occupied, skip the move and return the rover's current state (position and direction). Optionally, log the event for debugging or metrics.
Address concurrency (e.g., two rovers moving to the same cell), performance impact of collision checks, and whether to allow chaining of commands. Consider if the rover should attempt alternative moves.
Outline how you would test the behavior, including unit tests for collision scenarios and integration tests for concurrent moves. Summarize the solution's benefits and potential drawbacks.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.