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Build a Tic-Tac-Toe App

WhatnotSoftware Engineer · Technical Screen
MediumSoftware EngineerTechnical ScreenCoding & Algorithms

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This question evaluates proficiency in interactive UI development and stateful game logic, including turn management, board state representation, win/draw detection, input validation, and reset flow.

Implement a simple Tic-Tac-Toe mobile app that can be completed in a 45-minute coding interview.

Requirements:

  • Display a 3x3 board.
  • Support two local players, X and O, taking alternating turns.
  • A player can place a mark only in an empty cell.
  • After every move, detect whether either player has won by completing a row, column, or diagonal.
  • Detect a draw when the board is full and there is no winner.
  • Prevent additional moves after the game is over.
  • Show the current game status: current player, winner, or draw.
  • Provide a reset button to start a new game.

Focus on clean state management, readable UI code, and correctness rather than visual polish.