Simulate rover movement on a grid
Rover Navigation Simulator
This problem requires you to build a simulator for rover movement on a grid, starting with a basic 2D scenario and progressively extending it to support multiple rovers and a 3D environment.
Part 1: Single Rover on a 2D Map
You will be provided with:
- A rectangular 2D grid defined by
(x, y)coordinates. - A rover's initial starting position
(x0, y0)and its initial facing direction (one ofN, E, S, W). - A command string composed of the following instructions:
L: Turn the rover 90° to its left.R: Turn the rover 90° to its right.M: Move the rover forward one step in its current facing direction.
Rules:
- The rover must remain within the map boundaries. If a command would cause the rover to move out of bounds, that specific move should be ignored. (Alternatively, you may choose to return an error; if so, clearly state this chosen behavior and implement it consistently).
Task: Implement a function that, given the initial state and command string, returns the rover’s final position and direction after all commands have been executed.
Part 2: Multiple Rovers
Extend your design to accommodate multiple rovers operating on the same 2D map.
- Each rover will have its own distinct initial state (position and direction) and its own command string.
- You must clarify your assumption regarding how rovers execute commands: either sequentially (one rover completes all its commands before the next begins) or simultaneously step-by-step (all rovers execute their first command, then all execute their second, and so on).
- You must decide upon and implement a collision policy. For example, rovers might not be allowed to occupy the same cell, meaning a move that would result in a collision is rejected.
Task: Explain how you would modify your code structure and API to cleanly and safely support multiple rovers, incorporating your chosen execution and collision policies.
Part 3: 3D Map
Further extend your solution to support a 3D map with (x, y, z) coordinates.
- Define a reasonable model for orientation in 3D. Examples include a heading direction combined with pitch, or representing facing as one of six cardinal axes (
+X, -X, +Y, -Y, +Z, -Z). - Extend the command set as necessary to support 3D movement and orientation. If new commands are introduced, you must clearly specify them.
Task: Describe and/or implement how your solution generalizes to a 3D environment while maintaining a clean and extensible design.
AI interview prep
Core dilemma
The central engineering conflict is designing for extensibility and maintainability across increasing complexity (2D to 3D, single to multiple rovers) while managing state, interactions, and potential concurrency issues (collisions) efficiently and robustly.
3 tradeoffs and 3 stress tests locked
Interview prep
Unlock the interviewer X-Ray rubric, tradeoff matrix, stress tests, clarifying questions, and key concepts.
Simulate rover movement on a grid
Rover Navigation Simulator
This problem requires you to build a simulator for rover movement on a grid, starting with a basic 2D scenario and progressively extending it to support multiple rovers and a 3D environment.
Part 1: Single Rover on a 2D Map
You will be provided with:
- A rectangular 2D grid defined by
(x, y)coordinates. - A rover's initial starting position
(x0, y0)and its initial facing direction (one ofN, E, S, W). - A command string composed of the following instructions:
L: Turn the rover 90° to its left.R: Turn the rover 90° to its right.M: Move the rover forward one step in its current facing direction.
Rules:
- The rover must remain within the map boundaries. If a command would cause the rover to move out of bounds, that specific move should be ignored. (Alternatively, you may choose to return an error; if so, clearly state this chosen behavior and implement it consistently).
Task: Implement a function that, given the initial state and command string, returns the rover’s final position and direction after all commands have been executed.
Part 2: Multiple Rovers
Extend your design to accommodate multiple rovers operating on the same 2D map.
- Each rover will have its own distinct initial state (position and direction) and its own command string.
- You must clarify your assumption regarding how rovers execute commands: either sequentially (one rover completes all its commands before the next begins) or simultaneously step-by-step (all rovers execute their first command, then all execute their second, and so on).
- You must decide upon and implement a collision policy. For example, rovers might not be allowed to occupy the same cell, meaning a move that would result in a collision is rejected.
Task: Explain how you would modify your code structure and API to cleanly and safely support multiple rovers, incorporating your chosen execution and collision policies.
Part 3: 3D Map
Further extend your solution to support a 3D map with (x, y, z) coordinates.
- Define a reasonable model for orientation in 3D. Examples include a heading direction combined with pitch, or representing facing as one of six cardinal axes (
+X, -X, +Y, -Y, +Z, -Z). - Extend the command set as necessary to support 3D movement and orientation. If new commands are introduced, you must clearly specify them.
Task: Describe and/or implement how your solution generalizes to a 3D environment while maintaining a clean and extensible design.