I started with the move logic and immediately got tangled in the merge-once-per-move constraint.
Start by clarifying the requirements and edge cases, then outline a clean, modular design that separates board representation, move logic, and game state checks. Walk through the implementation of a single move (e.g., left) in detail, explaining how to handle shifting, merging, and spawning, and then generalize to other directions. Finally, discuss win/loss detection and potential optimizations or extensions.
Pro tip: Demonstrate test-driven development by mentioning specific test cases (e.g., merging two tiles, no merge when three identical tiles in a row, game over when no moves left) and how you would verify correctness. This shows attention to detail and quality.
Ask clarifying questions about grid size (fixed 4x4), win condition (2048 tile), and game over (no valid moves). Confirm that after each move, a new tile (2 or 4) spawns in an empty cell.
Represent the board as a 2D array (or list of lists). Define functions for shifting and merging a single row, and a function to apply a move in a given direction by transforming the board (e.g., rotate, shift left, rotate back).
For a left move, process each row: slide non-zero tiles to the left, merge adjacent equal tiles (only once per tile per move), slide again, and update score. For other directions, rotate the board, apply left move, and rotate back.
After a successful move (board changed), randomly select an empty cell and place a 2 (90% probability) or 4 (10%). Check for win if any tile equals 2048. Check for game over if no empty cells and no adjacent equal tiles.
Write unit tests for edge cases: merging multiple tiles, no merge when three in a row, game over detection. Discuss potential optimizations like using bitboards or precomputing row transformations for performance.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
This was the part I actually felt okay about.
Start by clarifying the game rules and the frontend's rendering needs, then design a response object that includes the updated board, merge details, new tile position, score, and game status. Emphasize that the API should be pure and return all necessary data for the UI to update without additional queries.
Pro tip: Consider versioning the API response or including a move ID to help the frontend handle optimistic updates and avoid race conditions. Also, think about how the frontend will animate merges and new tiles, so include enough metadata (like tile IDs) to support smooth transitions.
Ask about the game rules (e.g., 2048), frontend framework, and whether the API is for a single-player or multiplayer scenario. Confirm what information the frontend needs to render the UI and handle animations.
Outline the JSON structure: board (2D array of tile objects with id, value, position), merges (array of merged tile pairs with positions and new value), spawnedTile (object with id, value, position), score (current total), and status (e.g., 'ongoing', 'won', 'lost').
Describe how the move is processed: slide tiles, merge equal adjacent tiles, update score, spawn a new tile, and check game status. Ensure the response includes all changes for the frontend to render.
Address potential issues like invalid moves (return same state or error), performance (avoid sending full board if large), and how to handle animations (e.g., include previous positions for tiles that moved).
Mention how the API could be extended for features like undo, replay, or multiplayer sync. Discuss how the frontend would consume this API (e.g., REST, WebSocket) and any versioning strategy.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
Talked through keeping a pure game engine class that holds no UI knowledge, with the move function being a pure transformation on state.
Start by clarifying the game's requirements and constraints, then propose a layered architecture that cleanly separates state management, move logic, and rendering. Explain how each layer communicates through well-defined interfaces, and discuss trade-offs such as performance, testability, and maintainability.
Pro tip: Emphasize that separation of concerns enables independent testing and evolution of each layer, and mention how you would handle cross-cutting concerns like undo/redo or network synchronization without violating the boundaries.
Ask about the game type, real-time vs turn-based, platform, and performance needs to tailor your design.
Describe the state layer (data model), logic layer (rules and move validation), and rendering layer (UI), and what each should and shouldn't do.
Explain how layers interact: state notifies rendering of changes, logic reads/writes state, and rendering never mutates state directly.
Compare patterns like MVC, ECS, or observer, and discuss trade-offs in coupling, performance, and complexity.
Highlight how separation enables unit testing of logic and state, and makes it easier to add features like AI or multiplayer.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.