valid-sudoku.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
 https://leetcode.com/problems/valid-sudoku
"""
__author__ = "prakashsellathurai"
__copyright__ = "Copyright 2021"
__version__ = "1.0.1"
__email__ = "prakashsellathurai@gmail.com"


class Solution:
    @staticmethod
    def isValidSudoku(board: List[List[str]]) -> bool:

        boardMap = collections.defaultdict(list)
        for x in range(9):
            for y in range(9):
                char = board[x][y]
                if char != ".":
                    if char in boardMap:
                        for pos in boardMap[char]:
                            if (
                                (pos[0] == x)
                                or (pos[1] == y)
                                or (pos[0] // 3 == x // 3 and pos[1] // 3 == y // 3)
                            ):
                                return False
                    boardMap[char].append((x, y))

        return True