[LeetCode] 1275. Find Winner on a Tic Tac Toe Game

 Problem : https://leetcode.com/problems/find-winner-on-a-tic-tac-toe-game/

Keep tracking counters of the 3 rows / columns and the 2 diagonals.

Increase counter by 1 if it is player 'A' otherwise decrease counter by 1 for player 'B'.

Player 'A' wins if any counter equals to 3. Player 'B' wins if any counter equals to -3.

class Solution:
    def tictactoe(self, moves: List[List[int]]) -> str:
        rows = [0] * 3
        cols = [0] * 3
        
        diag1 = 0
        diag2 = 0
        
        for i, (y, x) in enumerate(moves):
            player = 1 if i & 1 == 0 else -1
           
            rows[y] += player
            cols[x] += player

            if y == x:
                diag1 += player

            if y == 2 - x:
                diag2 += player
        
            if rows[y] == 3 or cols[x] == 3 or diag1 == 3 or diag2 == 3:
                return 'A'

            if rows[y] == -3 or cols[x] == -3 or diag1 == -3 or diag2 == -3:
                return 'B'
            
        return 'Draw' if len(moves) >= 9 else 'Pending'