题解 | #Sudoku#

class Solution:
    def isValue(self, board, x, y):
        for i in range(9):  # 检查列
            if i != x and board[i][y] == board[x][y]:
                return False

        for j in range(9):
            if j != y and board[x][j] == board[x][y]:
                return False

        # 检查每个正方形是否符合
        m, n = 3 * (x // 3), 3 * (y // 3)  # 这里求出3x3网格的左上角的坐标
        for i in range(3):
            for j in range(3):
                if (i + m != x or j + n != y) and board[i + m][j + n] == board[x][y]:
                    return False

        return True
    
    def dfs(self,board):
        for i in range(9):
            for j in range(9):
                if board[i][j] == 0:
                    for k in '123456789':
                        board[i][j] = int(k)
                        if self.isValue(board,i,j) and self.dfs(board):
                            return True
                        board[i][j] = 0
                    return False
        return True


while True:
    try:
        board = []
        for i in range(9):
            row = list(map(int, input().split()))
            board.append(row)

        s = Solution()
        s.dfs(board)

        for i in range(9):
            board[i] = list(map(str, board[i]))
            print(" ".join(board[i]))
    except:
        break