You are given a a 9 x 9 Sudoku board board. A Sudoku board is valid if the following rules are followed:

Each row must contain the digits 1-9 without duplicates.
Each column must contain the digits 1-9 without duplicates.
Each of the nine 3 x 3 sub-boxes of the grid must contain the digits 1-9 without duplicates.
Return true if the Sudoku board is valid, otherwise return false

Note: A board does not need to be full or be solvable to be valid.

Example 1:



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

Output: true
Example 2:

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

Output: false
Explanation: There are two 1's in the top-left 3x3 sub-box.

Constraints:

board.length == 9
board[i].length == 9
board[i][j] is a digit 1-9 or '.'.

# Решение
Пусть будет матрица 3х3 где будут храниться числа в каждом квадрате валидации, т.е.
```
sq = [
    (), (), (),
    (), (), (),
    (), (), (),
]
```
Когда начнем  проходить по двумерной матрице - будем смотреть на номер строк и остаток деления на три от длины проверяемого столбца, чтобы определять в какой квадрат писать


i // 3
[
    0 0 0  0 0 0  0 0 0
    0 0 0  0 0 0  0 0 0
    0 0 0  0 0 0  0 0 0

    1 1 1  1 1 1  1 1 1
    1 1 1  1 1 1  1 1 1
    1 1 1  1 1 1  1 1 1

    2 2 2  2 2 2  2 2 2
    2 2 2  2 2 2  2 2 2
    2 2 2  2 2 2  2 2 2
]

j // 3
[
    0 0 0  1 1 1  2 2 2
    0 0 0  1 1 1  2 2 2
    0 0 0  1 1 1  2 2 2

    0 0 0  1 1 1  2 2 2
    0 0 0  1 1 1  2 2 2
    0 0 0  1 1 1  2 2 2

    0 0 0  1 1 1  2 2 2
    0 0 0  1 1 1  2 2 2
    0 0 0  1 1 1  2 2 2
]