class Solution: def isValidSudoku(self, board: List[List[str]]) -> bool:
for i in range(9):
l,m,k=set(),set(),set()
for j in range(9):
if board[i][j]!='.':
if board[i][j] in l :
return False
l.add(board[i][j])
if board[j][i]!='.':
if board[j][i] in m:
return False
m.add(board[j][i])
r=3*(i//3)+j//3
c=j%3+3*(i%3)
if board[r][c] != '.':
if board[r][c] in k:
return False
k.add(board[r][c])
return True