python-leetcode-有效的数独

36. 有效的数独 - 力扣（LeetCode）

class Solution:
    def isValidSudoku(self, board: List[List[str]]) -> bool:
        rows = [set() for _ in range(9)]
        cols = [set() for _ in range(9)]
        boxes = [set() for _ in range(9)]
        
        for i in range(9):
            for j in range(9):
                num = board[i][j]
                if num == '.':
                    continue
                
                # 检查行
                if num in rows[i]:
                    return False
                rows[i].add(num)
                
                # 检查列
                if num in cols[j]:
                    return False
                cols[j].add(num)
                
                # 检查 3x3 宫格
                box_index = (i // 3) * 3 + (j // 3)
                if num in boxes[box_index]:
                    return False
                boxes[box_index].add(num)
        
        return True