curriculum/challenges/english/blocks/learn-classes-and-objects-by-building-a-sudoku-solver/6606de006a82e05c9a65cebe.md
To verify that the number is valid after all those checks, call the all() function and pass it a list containing valid_in_row, valid_in_col, and valid_in_square. Also, return the result of the all() call.
You should return a call to the all() function passing it a list containing valid_in_row, valid_in_col, and valid_in_square.
({ test: () => assert(runPython(`
import itertools
p = list(itertools.permutations(["valid_in_row", "valid_in_col", "valid_in_square"]))
l = [", ".join(i) for i in p]
node = _Node(_code).find_class("Board").find_function("is_valid")
any([node.has_return(f"all([{i}])") for i in l])
`)) })
class Board:
def __init__(self, board):
self.board = board
def find_empty_cell(self):
for row, contents in enumerate(self.board):
try:
col = contents.index(0)
return row, col
except ValueError:
pass
return None
def valid_in_row(self, row, num):
return num not in self.board[row]
def valid_in_col(self, col, num):
return all(self.board[row][col] != num for row in range(9))
def valid_in_square(self, row, col, num):
row_start = (row // 3) * 3
col_start = (col // 3) * 3
for row_no in range(row_start, row_start + 3):
for col_no in range(col_start, col_start + 3):
if self.board[row_no][col_no] == num:
return False
return True
--fcc-editable-region--
def is_valid(self, empty, num):
row, col = empty
valid_in_row = self.valid_in_row(row, num)
valid_in_col = self.valid_in_col(col, num)
valid_in_square = self.valid_in_square(row, col, num)
--fcc-editable-region--
puzzle = [
[0, 0, 2, 0, 0, 8, 0, 0, 0],
[0, 0, 0, 0, 0, 3, 7, 6, 2],
[4, 3, 0, 0, 0, 0, 8, 0, 0],
[0, 5, 0, 0, 3, 0, 0, 9, 0],
[0, 4, 0, 0, 0, 0, 0, 2, 6],
[0, 0, 0, 4, 6, 7, 0, 0, 0],
[0, 8, 6, 7, 0, 4, 0, 0, 0],
[0, 0, 0, 5, 1, 9, 0, 0, 8],
[1, 7, 0, 0, 0, 6, 0, 0, 5]
]
gameboard = Board(puzzle)