← Early-stage Startup Interview Insights
My brain went straight to DFS across the board and the interviewer had to pull me back and tell me to just do it iteratively.
Start by clarifying requirements: board size, win condition, and whether it's a single game or multiple rounds. Then design a clean object-oriented solution with separate classes for Board, Player, and Game, using a 2D array for the board and checking for wins after each move. Focus on writing modular, testable code and discuss potential optimizations like early termination or bitboard representation.
Pro tip: Demonstrate production thinking by mentioning input validation, handling edge cases like a full board draw, and suggesting unit tests for win detection. Also, briefly discuss how you'd extend the design for an AI opponent or larger board, showing foresight and scalability.
Ask about board size (standard 3x3?), win condition (3 in a row?), number of players, and whether the game should support AI or just human players. Confirm if the program needs a UI or just the core logic.
Choose a representation for the board (e.g., 2D array of chars or integers) and define classes like Board, Player, and Game. Consider using enums for cell states (X, O, EMPTY) and a list to track moves for undo functionality.
Write methods for placing a move, checking for a win (rows, columns, diagonals), and detecting a draw. Ensure the game loop alternates turns and validates moves (e.g., cell not already taken).
Mention writing unit tests for win conditions, draw scenarios, and invalid moves. Discuss handling a full board, early termination when a player wins, and input validation.
Talk about how to extend the design for an AI player (minimax), larger boards, or a GUI. Mention potential optimizations like bitboards for win checking or using a 1D array for efficiency.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
Start by clarifying the rules and scope, then outline a data model that generalizes the existing tic-tac-toe board to a 3x3 grid of sub-boards. Discuss the game state representation, move validation, win detection, and how to handle the 'send to board' mechanic, emphasizing modularity and testability.
Pro tip: Mention that you would write unit tests for edge cases like a sub-board being won but not closed, or a player being sent to a full board, to demonstrate thoroughness and reliability—key for early-stage startups where code quality matters.
Ask about specific rules: how the next board is determined, what happens if sent to a completed board, and win conditions. Confirm whether the implementation should be object-oriented or functional, and any performance considerations.
Propose a Board class that contains a 3x3 array of sub-boards (each a standard tic-tac-toe board) and a meta-board tracking the status of each sub-board. Include state for current player, active sub-board, and overall game status.
Detail how to validate moves: check if the target sub-board is active and not completed, and if the cell is empty. Update the active sub-board based on the move's cell position, handling cases where the target sub-board is already won or full.
Explain how to detect wins in sub-boards and then in the meta-board. After each move, check if the sub-board is won and update the meta-board; then check if the meta-board has a winner or if the game is a draw.
Outline a testing strategy covering normal moves, edge cases (e.g., forced moves to completed boards), and win conditions. Mention how the design allows for future extensions like AI players or different board sizes.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.