36. Valid Sudoku

Determine if a 9x9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:

  1. Each row must contain the digits 1-9 without repetition.
  2. Each column must contain the digits 1-9 without repetition.
  3. Each of the 9 3x3 sub-boxes of the grid must contain the digits 1-9 without repetition.

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A partially filled sudoku which is valid.

The Sudoku board could be partially filled, where empty cells are filled with the character '.'.

Example 1:

Input:
[
["5","3",".",".","7",".",".",".","."],
["6",".",".","1","9","5",".",".","."],
[".","9","8",".",".",".",".","6","."],
["8",".",".",".","6",".",".",".","3"],
["4",".",".","8",".","3",".",".","1"],
["7",".",".",".","2",".",".",".","6"],
[".","6",".",".",".",".","2","8","."],
[".",".",".","4","1","9",".",".","5"],
[".",".",".",".","8",".",".","7","9"]
]
Output: true

Example 2:

Input:
[
["8","3",".",".","7",".",".",".","."],
["6",".",".","1","9","5",".",".","."],
[".","9","8",".",".",".",".","6","."],
["8",".",".",".","6",".",".",".","3"],
["4",".",".","8",".","3",".",".","1"],
["7",".",".",".","2",".",".",".","6"],
[".","6",".",".",".",".","2","8","."],
[".",".",".","4","1","9",".",".","5"],
[".",".",".",".","8",".",".","7","9"]
]
Output: false
Explanation: Same as Example 1, except with the 5 in the top left corner being
modified to 8. Since there are two 8's in the top left 3x3 sub-box, it is invalid.

Note:

  • A Sudoku board (partially filled) could be valid but is not necessarily solvable.
  • Only the filled cells need to be validated according to the mentioned rules.
  • The given board contain only digits 1-9 and the character '.'.
  • The given board size is always 9x9.
class Solution:
    def isValidSudoku(self, board):
        """
        :type board: List[List[str]]
        :rtype: bool
        """
        def line():
            for i in range(9):
                ans = [0 for _ in range(10)]
                for j in range(9):
                    if board[i][j]=='.':
                        continue
                    ans[int(board[i][j])] += 1
                for t in ans:
                    if t>1:
                        return False
            return True
        def coloum():
            for j in range(9):
                ans = [0 for _ in range(10)]
                for i in range(9):
                    if board[i][j]=='.':
                        continue
                    ans[int(board[i][j])] += 1
                # print(j,'
',ans)
                for t in ans:
                    if t>1:
                        return False
            return True
        def boxes(a,b,c,d):
            ans = [0 for _ in range(10)]
            for i in range(a,b):
                for j in range(c,d):
                    if board[i][j]=='.':
                        continue
                    ans[int(board[i][j])] += 1
            for t in ans:
                if t>1:
                    return False
            return True
        if line() and coloum() and boxes(0,3,0,3) and boxes(3,6,0,3) and boxes(6,9,0,3) and boxes(0,3,3,6) and boxes(3,6,3,6) and boxes(6,9,3,6) and boxes(0,3,6,9) and boxes(3,6,6,9) and boxes(6,9,6,9):
            return True
        return False
原文地址:https://www.cnblogs.com/bernieloveslife/p/9791920.html