leetcode学习笔记(有效数独)

class Solution:
    def isValidSudoku(self, board):
        row = [[0] * 9 for _ in range(9)] #9行里每行1——9每个数字出现次数
        col = [[0] * 9 for _ in range(9)]
        box = [[0] * 9 for _ in range(9)] #每个方框里
        
        for i in range(9):
            for j in range(9):
                if board[i][j] == '.':
                    continue
                curNum = ord(board[i][j]) - ord('1')
                if row[i][curNum] != 0 or col[j][curNum] != 0 or box[j // 3 + (i // 3) * 3][curNum] != 0:
                    return False
                row[i][curNum], col[j][curNum],box[j // 3 + (i // 3) * 3][curNum] = 1, 1, 1
        return True

ord(): 参数是长度为1的字符，返回的是对应的Unicode 数值