def test_unique_rectangle_block_apart():
sudoku = make_sudoku_with_marks(
[
[9, 0, 1, 0, 3, 0, 5, 0, 0],
[0, 0, 7, 8, 1, 9, 0, 0, 0],
[0, 2, 0, 4, 5, 6, 1, 9, 7],
[1, 0, 2, 9, 0, 0, 6, 0, 5],
[0, 0, 0, 6, 7, 1, 0, 2, 4],
[6, 0, 0, 3, 2, 5, 8, 0, 0],
[0, 1, 5, 0, 9, 0, 4, 6, 3],
[0, 0, 6, 5, 0, 0, 0, 0, 0],
[0, 0, 0, 1, 6, 3, 0, 5, 0],
],
box_size=BoxSize(3, 3),
)
unique_rectangle = techniques.UniqueRectangle(sudoku).first()
assert unique_rectangle.combination.cells == [
Cell(position=Position(0, 3, 1), candidates={2, 7}),
Cell(position=Position(0, 5, 1), candidates={2, 7}),
Cell(position=Position(6, 3, 7), candidates={2, 7}),
Cell(position=Position(6, 5, 7), candidates={2, 7, 8}),
]
assert unique_rectangle.changes == [
Cell(position=Position(6, 5, 7), candidates={8})
]
def test_locked_candidate_in_a_row():
sudoku = make_sudoku_with_marks(
[
[9, 0, 0, 5, 3, 1, 2, 8, 0],
[0, 2, 5, 7, 0, 4, 9, 3, 0],
[0, 3, 0, 0, 0, 2, 0, 4, 0],
[4, 8, 1, 2, 5, 7, 6, 9, 3],
[3, 5, 9, 0, 0, 8, 0, 0, 2],
[7, 6, 2, 3, 1, 9, 8, 5, 4],
[0, 1, 0, 0, 0, 0, 0, 6, 8],
[6, 0, 8, 1, 0, 5, 3, 0, 0],
[0, 0, 3, 8, 7, 6, 0, 0, 0],
],
box_size=BoxSize(3, 3),
)
locked_candidate = techniques.LockedCandidate(sudoku).first()
assert locked_candidate.combination.cells == [
Cell(position=Position(6, 3, 7), candidates={4, 9}),
Cell(position=Position(6, 4, 7), candidates={2, 4, 9}),
]
assert locked_candidate.combination.values == [9]
assert locked_candidate.changes == [
Cell(position=Position(7, 4, 7), candidates={2, 4})
]
def test_naked_triplet():
sudoku = make_sudoku_with_marks(
[
[9, 2, 6, 7, 3, 5, 4, 0, 0],
[0, 0, 0, 6, 4, 9, 7, 2, 5],
[7, 4, 5, 8, 2, 1, 9, 3, 6],
[0, 1, 0, 0, 0, 8, 6, 4, 0],
[5, 0, 4, 0, 0, 0, 8, 0, 0],
[8, 6, 9, 1, 7, 4, 3, 5, 2],
[0, 0, 0, 0, 8, 0, 0, 0, 0],
[0, 0, 0, 9, 1, 0, 0, 6, 0],
[0, 0, 0, 4, 0, 3, 1, 0, 0],
],
box_size=BoxSize(3, 3),
)
naked_triplet = techniques.NakedTriplet(sudoku).first()
assert naked_triplet.combination.cells == [
Cell(position=Position(6, 7, 8), candidates={7, 9}),
Cell(position=Position(8, 7, 8), candidates={7, 8, 9}),
Cell(position=Position(8, 8, 8), candidates={7, 8, 9}),
]
assert naked_triplet.combination.values == [7, 8, 9]
by_position = operator.attrgetter("position")
assert sorted(naked_triplet.changes, key=by_position) == [
Cell(position=Position(6, 8, 8), candidates={3, 4}),
Cell(position=Position(7, 8, 8), candidates={3, 4}),
]
def test_unique_rectangle_not_found():
sudoku = make_sudoku_with_marks(
[
[9, 2, 6, 7, 3, 5, 4, 0, 0],
[0, 0, 0, 6, 4, 9, 7, 2, 5],
[7, 4, 5, 8, 2, 1, 9, 3, 6],
[0, 1, 0, 0, 0, 8, 6, 4, 0],
[5, 0, 4, 0, 0, 0, 8, 0, 0],
[8, 6, 9, 1, 7, 4, 3, 5, 2],
[0, 0, 0, 0, 8, 0, 0, 0, 0],
[0, 0, 0, 9, 1, 0, 0, 6, 0],
[0, 0, 0, 4, 0, 3, 1, 0, 0],
],
box_size=BoxSize(3, 3),
)
sudoku.update([
Cell(position=Position(6, 0, 6), candidates={1, 6}),
Cell(position=Position(6, 8, 8), candidates={3, 4}),
Cell(position=Position(7, 0, 6), candidates={3, 4}),
Cell(position=Position(7, 8, 8), candidates={3, 4}),
])
with pytest.raises(techniques.NotFound):
techniques.UniqueRectangle(sudoku).first()
def _random_initial_cells(box_size: BoxSize) -> List[Cell]:
size = box_size.width * box_size.length
all_values = set(range(1, size + 1))
values = random.sample(all_values, k=size)
box_values = [
values[i * box_size.length:i * box_size.length + box_size.length]
for i in range(box_size.width)
]
while True: # pragma: no branch
row_values = random.sample(all_values - set(box_values[0]),
k=box_size.length)
used_values = [sorted(box_values[i]) for i in range(1, box_size.width)]
if sorted(row_values) not in used_values:
break
row_values += random.sample(all_values.difference(box_values[0],
row_values),
k=box_size.length)
return [
Cell(
position=Position(row=i, column=j, box=box_size.sequential(i, j)),
value=box_values[i][j],
) for i in range(box_size.width) for j in range(box_size.length)
] + [
Cell(
position=Position(row=0, column=i, box=box_size.sequential(0, i)),
value=value,
) for i, value in enumerate(row_values, start=box_size.length)
]
def test_hidden_single():
sudoku = make_sudoku_with_marks(
[
[9, 0, 6, 7, 0, 5, 0, 0, 0],
[0, 0, 0, 0, 0, 9, 0, 2, 5],
[7, 4, 0, 0, 0, 1, 0, 0, 0],
[0, 1, 0, 0, 0, 0, 6, 4, 0],
[5, 0, 0, 0, 0, 0, 0, 0, 0],
[8, 6, 9, 1, 0, 0, 3, 0, 0],
[0, 0, 0, 0, 8, 0, 0, 0, 0],
[0, 0, 0, 9, 0, 0, 0, 6, 0],
[0, 0, 0, 4, 0, 3, 1, 0, 0],
],
box_size=BoxSize(3, 3),
)
hidden_single = techniques.HiddenSingle(sudoku).first()
assert hidden_single.combination.cells == [
Cell(position=Position(1, 6, 2), candidates={4, 7, 8})
]
assert hidden_single.combination.values == [7]
by_position = operator.attrgetter("position")
assert sorted(hidden_single.changes, key=by_position) == [
Cell(position=Position(1, 6, 2), value=7),
Cell(position=Position(4, 6, 5), candidates={2, 8, 9}),
Cell(position=Position(6, 6, 8), candidates={2, 4, 5, 9}),
Cell(position=Position(7, 6, 8), candidates={2, 4, 5, 8}),
]
def test_unique_rectangle():
sudoku = make_sudoku_with_marks(
[
[0, 6, 0, 8, 0, 2, 3, 7, 1],
[3, 0, 7, 1, 6, 5, 8, 0, 4],
[0, 8, 1, 3, 7, 0, 5, 6, 0],
[8, 7, 4, 9, 2, 3, 1, 5, 6],
[9, 1, 3, 6, 5, 8, 2, 4, 7],
[6, 0, 0, 4, 1, 7, 9, 3, 8],
[0, 3, 8, 0, 0, 0, 6, 1, 5],
[0, 0, 6, 0, 8, 1, 4, 0, 3],
[1, 4, 0, 5, 3, 6, 7, 8, 0],
],
box_size=BoxSize(3, 3),
)
assert len(list(techniques.UniqueRectangle(sudoku))) == 1
unique_rectangle = techniques.UniqueRectangle(sudoku).first()
assert unique_rectangle.combination.cells == [
Cell(position=Position(6, 0, 6), candidates={2, 7}),
Cell(position=Position(6, 3, 7), candidates={2, 7}),
Cell(position=Position(7, 0, 6), candidates={2, 5, 7}),
Cell(position=Position(7, 3, 7), candidates={2, 7}),
]
assert unique_rectangle.combination.values == [2, 7]
assert unique_rectangle.changes == [
Cell(position=Position(7, 0, 6), candidates={5}),
]
def test_lone_single():
sudoku = make_sudoku_with_marks(
[
[0, 0, 0, 0, 9, 0, 1, 0, 0],
[0, 0, 0, 0, 0, 2, 3, 0, 0],
[0, 0, 7, 0, 0, 1, 8, 2, 5],
[6, 0, 4, 0, 3, 8, 9, 0, 0],
[8, 1, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 9, 0, 0, 0, 0, 0, 8],
[1, 7, 0, 0, 0, 0, 6, 0, 0],
[9, 0, 0, 0, 1, 0, 7, 4, 3],
[4, 0, 3, 0, 6, 0, 0, 0, 1],
],
box_size=BoxSize(3, 3),
)
lone_single = techniques.LoneSingle(sudoku).first()
assert lone_single.combination.cells == [
Cell(position=Position(1, 0, 0), candidates={5})
]
assert lone_single.combination.values == [5]
by_position = operator.attrgetter("position")
assert sorted(lone_single.changes, key=by_position) == [
Cell(position=Position(0, 0, 0), candidates={2, 3}),
Cell(position=Position(0, 1, 0), candidates={2, 3, 4, 6, 8}),
Cell(position=Position(0, 2, 0), candidates={2, 6, 8}),
Cell(position=Position(1, 0, 0), value=5),
Cell(position=Position(1, 1, 0), candidates={4, 6, 8, 9}),
Cell(position=Position(1, 2, 0), candidates={1, 6, 8}),
Cell(position=Position(1, 3, 1), candidates={4, 6, 7, 8}),
Cell(position=Position(1, 4, 1), candidates={4, 7, 8}),
Cell(position=Position(5, 0, 3), candidates={2, 3, 7}),
]
def test_sudoku():
sudoku = Sudoku(
Cell(position=Position(0, 0, 0), value=2),
Cell(position=Position(0, 1, 0), candidates=set()),
box_size=BoxSize(3, 3),
)
assert sudoku[0, 0].value == 2
assert sudoku[0, 1].candidates == set()
assert sudoku[0, 2].value is None
assert len(sudoku[0, 2].candidates) == 0
def test_locked_candidate_not_found():
sudoku = make_sudoku_with_marks(
[
[2, 0, 0, 5, 9, 3, 1, 0, 0],
[5, 0, 1, 0, 0, 2, 3, 0, 0],
[3, 9, 7, 6, 4, 1, 8, 2, 5],
[6, 0, 4, 0, 3, 8, 9, 0, 0],
[8, 1, 0, 0, 0, 0, 0, 3, 6],
[7, 3, 9, 0, 0, 6, 0, 0, 8],
[1, 7, 0, 3, 0, 4, 6, 0, 0],
[9, 0, 0, 0, 1, 5, 7, 4, 3],
[4, 0, 3, 0, 6, 0, 0, 0, 1],
],
box_size=BoxSize(3, 3),
)
sudoku.update([
Cell(position=Position(1, 1, 0), candidates={4, 6}),
Cell(position=Position(1, 7, 2), candidates={6, 9}),
Cell(position=Position(1, 8, 2), candidates={4, 9}),
Cell(position=Position(3, 3, 4), candidates={1, 2}),
Cell(position=Position(8, 1, 6), candidates={2, 5, 8}),
Cell(position=Position(8, 3, 7), candidates={7, 9}),
Cell(position=Position(8, 5, 7), candidates={7, 9}),
Cell(position=Position(8, 6, 8), candidates={2, 5}),
Cell(position=Position(8, 7, 8), candidates={5, 8}),
])
with pytest.raises(techniques.NotFound):
techniques.LockedCandidate(sudoku).first()
def test_combination_as_str():
combination = techniques.Combination(
name="Naked Pair",
cells=[
Cell(position=Position(6, 3, 7), candidates={2, 5}),
Cell(position=Position(6, 6, 8), candidates={2, 5}),
],
values=[2, 5],
)
assert str(combination) == "Naked Pair: `2, 5` at (6, 3), (6, 6)"
def _get_changes(self, combination: Combination) -> List[Cell]:
eliminated = set(combination.values)
single = Cell(
position=combination.cells[0].position,
value=combination.values[0],
)
return [
Cell(position=cell.position,
candidates=cell.candidates - eliminated)
for cell in self.sudoku.intersection(single)
if cell.candidates and cell.candidates & eliminated
] + [single]
def test_locked_candidate_in_a_box():
sudoku = make_sudoku_with_marks(
[
[2, 0, 0, 5, 9, 3, 1, 0, 0],
[5, 0, 1, 0, 0, 2, 3, 0, 0],
[3, 9, 7, 6, 4, 1, 8, 2, 5],
[6, 0, 4, 0, 3, 8, 9, 0, 0],
[8, 1, 0, 0, 0, 0, 0, 3, 6],
[7, 3, 9, 0, 0, 6, 0, 0, 8],
[1, 7, 0, 3, 0, 4, 6, 0, 0],
[9, 0, 0, 0, 1, 5, 7, 4, 3],
[4, 0, 3, 0, 6, 0, 0, 0, 1],
],
box_size=BoxSize(3, 3),
)
sudoku.update([
Cell(position=Position(1, 1, 0), candidates={4, 6}),
Cell(position=Position(1, 7, 2), candidates={6, 9}),
Cell(position=Position(1, 8, 2), candidates={4, 9}),
Cell(position=Position(8, 3, 7), candidates={7, 9}),
Cell(position=Position(8, 7, 8), candidates={5, 8}),
])
locked_candidate = techniques.LockedCandidate(sudoku).first()
assert locked_candidate.combination.cells == [
Cell(position=Position(3, 7, 5), candidates={1, 5, 7}),
Cell(position=Position(3, 8, 5), candidates={2, 7}),
]
assert locked_candidate.combination.values == [7]
assert locked_candidate.changes == [
Cell(position=Position(3, 3, 4), candidates={1, 2})
]
def count(sudoku: Sudoku) -> None:
nonlocal total_solutions
nonlocal total_branch_factor
_sudoku = solvers.eliminate(sudoku)
cells = sorted(
(cell for cell in _sudoku.cells() if not cell.value),
key=operator.attrgetter("candidates"),
)
for cell in cells:
branch_factor = len(cell.candidates)
for candidate in cell.candidates:
_sudoku.update([Cell(position=cell.position, value=candidate)])
try:
count(_sudoku)
except (exceptions.InvalidSudoku, exceptions.NoCandidates):
pass
else:
total_solutions += 1
if total_solutions > 1:
raise exceptions.MultipleSolutions
total_branch_factor += pow(branch_factor - 1, 2)
_sudoku.update([cell])
else:
raise exceptions.NoCandidates
def _get_changes(self, combination: Combination) -> List[Cell]:
eliminated = set(combination.values)
return [
Cell(position=cell.position, candidates=diff)
for cell in combination.cells
if (diff := cell.candidates - eliminated)
]
def _get_changes(self, combination: Combination) -> List[Cell]:
eliminated = set(combination.values)
return [
Cell(position=c.position, candidates=c.candidates - eliminated)
for c in self.sudoku.intersection(
*[x for x in combination.cells[::2]])
if c.candidates and c.candidates & eliminated
]
def _get_changes(self, combination: Combination) -> List[Cell]:
result = []
for cell in combination.cells:
candidates = self._get_candidates(cell)
if not cell.candidates or cell.candidates - candidates:
result.append(
Cell(position=cell.position, candidates=candidates))
return result
def test_hint_for_invalid_sudoku(rf):
sudoku = generators.random_sudoku(avg_rank=1)
sudoku.update(techniques.BulkPencilMarking(sudoku).first().changes)
sudoku.update(
[
Cell(position=Position(0, 0, 0), value=1),
Cell(position=Position(0, 1, 0), value=1),
]
)
url = reverse("hint")
serializer = serializers.SudokuSerializer(sudoku)
request = rf.post(url, data=serializer.data, content_type="application/json")
response = views.Hints.as_view()(request)
content = json.loads(response.rendered_content)
assert content["code"] == "invalid_puzzle"
assert response.status_code == 400
def create(self, validated_data):
return Sudoku(
*[
Cell(
position=Position(*cell["position"]),
value=cell["value"],
candidates=set(cell["candidates"]),
) for cell in validated_data["cells"]
],
box_size=BoxSize(*validated_data["box_size"]),
)
def test_pencil_marking_corrects_invalid_mark():
sudoku = make_sudoku_with_marks(
[
[0, 0, 0, 0, 9, 0, 1, 0, 0],
[0, 0, 0, 0, 0, 2, 3, 0, 0],
[0, 0, 7, 0, 0, 1, 8, 2, 5],
[6, 0, 4, 0, 3, 8, 9, 0, 0],
[8, 1, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 9, 0, 0, 0, 0, 0, 8],
[1, 7, 0, 0, 0, 0, 6, 0, 0],
[9, 0, 0, 0, 1, 0, 7, 4, 3],
[4, 0, 3, 0, 6, 0, 0, 0, 1],
],
box_size=BoxSize(3, 3),
)
sudoku.update([Cell(position=Position(1, 0, 0), candidates={3, 5})])
pencil_marks = techniques.PencilMarking(sudoku).first()
assert pencil_marks.changes == [
Cell(position=Position(1, 0, 0), candidates={5})
]
def test_naked_pair():
sudoku = make_sudoku_with_marks(
[
[9, 2, 6, 7, 3, 5, 4, 0, 0],
[0, 0, 0, 6, 4, 9, 7, 2, 5],
[7, 4, 5, 8, 2, 1, 9, 3, 6],
[0, 1, 0, 0, 0, 8, 6, 4, 0],
[5, 0, 4, 0, 0, 0, 8, 0, 0],
[8, 6, 9, 1, 7, 4, 3, 5, 2],
[0, 0, 0, 0, 8, 0, 0, 0, 0],
[0, 0, 0, 9, 1, 0, 0, 6, 0],
[0, 0, 0, 4, 0, 3, 1, 0, 0],
],
box_size=BoxSize(3, 3),
)
naked_pair = techniques.NakedPair(sudoku).first()
assert naked_pair.combination.cells == [
Cell(position=Position(6, 3, 7), candidates={2, 5}),
Cell(position=Position(6, 6, 8), candidates={2, 5}),
]
assert naked_pair.combination.values == [2, 5]
by_position = operator.attrgetter("position")
assert sorted(naked_pair.changes, key=by_position) == [
Cell(position=Position(6, 0, 6), candidates={1, 3, 4, 6}),
Cell(position=Position(6, 1, 6), candidates={3, 7, 9}),
Cell(position=Position(6, 2, 6), candidates={1, 3, 7}),
Cell(position=Position(6, 5, 7), candidates={6, 7}),
]
def test_xy_wing():
sudoku = make_sudoku_with_marks(
[
[2, 0, 0, 5, 9, 3, 1, 0, 0],
[5, 0, 1, 0, 0, 2, 3, 0, 0],
[3, 9, 7, 6, 4, 1, 8, 2, 5],
[6, 0, 4, 0, 3, 8, 9, 0, 0],
[8, 1, 0, 0, 0, 0, 0, 3, 6],
[7, 3, 9, 0, 0, 6, 0, 0, 8],
[1, 7, 0, 3, 0, 4, 6, 0, 0],
[9, 0, 0, 0, 1, 5, 7, 4, 3],
[4, 0, 3, 0, 6, 0, 0, 0, 1],
],
box_size=BoxSize(3, 3),
)
sudoku.update([Cell(position=Position(3, 3, 4), candidates={1, 2})])
xy_wing = techniques.XYWing(sudoku).first()
assert xy_wing.combination.cells == [
Cell(position=Position(3, 3, 4), candidates={1, 2}),
Cell(position=Position(5, 4, 4), candidates={2, 5}),
Cell(position=Position(5, 7, 5), candidates={1, 5}),
]
assert xy_wing.combination.values == [1]
assert xy_wing.changes == [
Cell(position=Position(3, 7, 5), candidates={5, 7}),
Cell(position=Position(5, 3, 4), candidates={2, 4}),
]
def test_naked_pair_not_found():
sudoku = make_sudoku_with_marks(
[
[9, 2, 6, 7, 3, 5, 4, 0, 0],
[0, 0, 0, 6, 4, 9, 7, 2, 5],
[7, 4, 5, 8, 2, 1, 9, 3, 6],
[0, 1, 0, 0, 0, 8, 6, 4, 0],
[5, 0, 4, 0, 0, 0, 8, 0, 0],
[8, 6, 9, 1, 7, 4, 3, 5, 2],
[0, 0, 0, 0, 8, 0, 0, 0, 0],
[0, 0, 0, 9, 1, 0, 0, 6, 0],
[0, 0, 0, 4, 0, 3, 1, 0, 0],
],
box_size=BoxSize(3, 3),
)
sudoku.update([
Cell(position=Position(6, 0, 6), candidates={1, 3, 4, 6}),
Cell(position=Position(6, 1, 6), candidates={3, 7, 9}),
Cell(position=Position(6, 2, 6), candidates={1, 3, 7}),
Cell(position=Position(6, 5, 7), candidates={6, 7}),
])
with pytest.raises(techniques.NotFound):
techniques.NakedPair(sudoku).first()
def random_sudoku(avg_rank: int = 150,
box_size: BoxSize = BoxSize(3, 3)) -> Sudoku:
sudoku = Sudoku(*_random_initial_cells(box_size), box_size=box_size)
solution = solvers.backtrack(sudoku)
iterations = min(avg_rank, MAX_ITERATIONS)
for i in range(iterations):
size = random.randint(1, 2)
rows = [random.randint(0, solution.size - 1) for _ in range(size)]
columns = [random.randint(0, solution.size - 1) for _ in range(size)]
cells = [solution[row, column] for (row, column) in zip(rows, columns)]
if all(cell.value for cell in cells):
solution.update([Cell(position=cell.position) for cell in cells])
try:
stats.rank(solution)
except exceptions.MultipleSolutions:
solution.update(cells)
return solution
def backtrack(sudoku: Sudoku) -> Sudoku:
_sudoku = eliminate(sudoku)
cells = sorted(
(cell for cell in _sudoku.cells() if not cell.value),
key=operator.attrgetter("candidates"),
)
for cell in cells:
for candidate in cell.candidates:
_sudoku.update([Cell(position=cell.position, value=candidate)])
try:
return backtrack(_sudoku)
except (exceptions.InvalidSudoku, exceptions.NoCandidates):
pass
_sudoku.update([cell])
else:
raise exceptions.NoCandidates
return _sudoku
def test_pencil_marking():
sudoku = Sudoku.from_list(
[
[0, 0, 0, 0, 9, 0, 1, 0, 0],
[0, 0, 0, 0, 0, 2, 3, 0, 0],
[0, 0, 7, 0, 0, 1, 8, 2, 5],
[6, 0, 4, 0, 3, 8, 9, 0, 0],
[8, 1, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 9, 0, 0, 0, 0, 0, 8],
[1, 7, 0, 0, 0, 0, 6, 0, 0],
[9, 0, 0, 0, 1, 0, 7, 4, 3],
[4, 0, 3, 0, 6, 0, 0, 0, 1],
],
box_size=BoxSize(3, 3),
)
pencil_marks = techniques.PencilMarking(sudoku).first()
assert pencil_marks.changes == [
Cell(position=Position(0, 0, 0), candidates={2, 3, 5})
]
def test_getitem(sudoku):
assert sudoku[0, 0] == Cell(position=Position(0, 0, 0), candidates=set())
assert sudoku[2, 3] == Cell(position=Position(2, 3, 1), value=9)
def test_cell():
with pytest.raises(ValueError):
Cell(position=Position(0, 0, 0), value=2, candidates={2, 6, 9})
def test_update(sudoku):
cell_a = Cell(position=Position(0, 0, 0), value=2)
cell_b = Cell(position=Position(0, 1, 0), candidates=set())
sudoku.update([cell_a, cell_b])
assert sudoku[0, 0] is cell_a
assert sudoku[0, 1] is cell_b