Design Tic Tac Toe

Design a TicTacToe class for an n x n board.

Two players take turns placing marks on the board. Player 1 plays first. Implement:

• TicTacToe(int n) — initialise an n x n empty board.
• move(int row, int col, int player) -> int — record player (1 or 2) playing at (row, col). Moves are guaranteed to be on empty cells. Returns:
  • 0 if no winner yet
  • 1 if player 1 just won
  • 2 if player 2 just won

A player wins by placing n of their marks in any horizontal, vertical, or one of the two diagonal lines.

Bonus: the move check must run in O(1) per call (no full board scan).

Examples:

n = 3 move(0,0,1) -> 0 move(0,1,2) -> 0 move(1,0,1) -> 0 move(1,1,2) -> 0 move(2,0,1) -> 1 (player 1 fills column 0)

Follow-up Questions:

• Add an API for the current player to make a random valid move.
• How would you generalise this to k-in-a-row on an n x n board?