The answer
Create a 3x3 grid. Use an array of 9 elements for the board. Alternate players (X/O). After each move, check 8 win patterns (3 rows, 3 columns, 2 diagonals). Detect draw when all cells are filled. Add reset and score tracking.
How to Build a Tic-Tac-Toe Game in an Interview
How do I build a tic-tac-toe game in a machine coding interview?
More FAQs in How to Build a Tic-Tac-Toe Game in an Interview
Check 8 win patterns: [[0,1,2], [3,4,5], [6,7,8], [0,3,6], [1,4,7], [2,5,8], [0,4,8], [2,4,6]]. For each pattern, if board[a] === board[b] === board[c] and board[a] is not null, that player wins.
Check if all cells are filled (board.every(cell => cell !== null)) and no winner was detected. If so, it is a draw. Check for a win first, then check for a draw.
Clicking an already-filled cell (ignore), clicking after game over (ignore), highlighting the winning cells, score tracking (X wins, O wins, draws), and reset button to start a new game.
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