def test_get_box_from_index():
sudoku_board = Sudoku(boards.unsolved_easy)
box1 = sudoku_board.get_box_from_index(0)
expected_box1 = array([[5, 3, 0], [6, 0, 0], [0, 9, 8]])
assert (box1 == expected_box1).all()
box2 = sudoku_board.get_box_from_index(1)
expected_box2 = array([[0, 7, 0], [1, 9, 5], [0, 0, 0]])
assert (box2 == expected_box2).all()
box3 = sudoku_board.get_box_from_index(2)
expected_box3 = array([[0, 0, 0], [0, 0, 0], [0, 6, 0]])
assert (box3 == expected_box3).all()
box4 = sudoku_board.get_box_from_index(3)
expected_box4 = array([[8, 0, 0], [4, 0, 0], [7, 0, 0]])
assert (box4 == expected_box4).all()
box5 = sudoku_board.get_box_from_index(4)
expected_box5 = array([[0, 6, 0], [8, 0, 3], [0, 2, 0]])
assert (box5 == expected_box5).all()
box6 = sudoku_board.get_box_from_index(5)
expected_box6 = array([[0, 0, 3], [0, 0, 1], [0, 0, 6]])
assert (box6 == expected_box6).all()
box7 = sudoku_board.get_box_from_index(6)
expected_box7 = array([[0, 6, 0], [0, 0, 0], [0, 0, 0]])
assert (box7 == expected_box7).all()
box8 = sudoku_board.get_box_from_index(7)
expected_box8 = array([[0, 0, 0], [4, 1, 9], [0, 8, 0]])
assert (box8 == expected_box8).all()
box9 = sudoku_board.get_box_from_index(8)
expected_box9 = array([[2, 8, 0], [0, 0, 5], [0, 7, 9]])
assert (box9 == expected_box9).all()
def crosshatch_box(sudoku: sudoku_board.Sudoku, box_number: int) -> bool:
all_values = [1, 2, 3, 4, 5, 6, 7, 8, 9]
unused_values = []
box = sudoku.get_box_from_index(box_number)
box_values = box.flatten()
for value in all_values:
if value not in box_values:
unused_values.append(value)
solved_value = False
# Loop through each value that is not in the box.
for value in unused_values:
possible_rows = []
possible_columns = []
# Check each row that goes through the box.
for row in get_rows_from_box_index(box_number):
# If the value is not in that row then it could be in that row of the box.
if not check_row_for_value(sudoku, row, value):
possible_rows.append(row)
# Check each column that goes through the box.
for column in get_columns_from_box_index(box_number):
# If the value is not in that column then it could be in that column of the box.
if not check_column_for_value(sudoku, column, value):
possible_columns.append(column)
# Remove duplicates from possible rows and columns.
possible_rows = list(set(possible_rows))
possible_columns = list(set(possible_columns))
# A cell position is only possible if the value is 0. Save the index if it is.
possible_index = []
for row in possible_rows:
for column in possible_columns:
if sudoku.board_numbers[row, column] == 0:
possible_index.append([row, column])
# If there is only one possible value for this cell then add it to the board.
if len(possible_index) == 1:
sudoku.add_cell(possible_index[0][0], possible_index[0][1], value)
solved_value = True
return solved_value