class TestDigger(unittest.TestCase):
def setUp(self):
digging_strategy = DiggingStrategy(1)
self.digger = Digger(digging_strategy)
self.terminal_pattern = generate_terminal_pattern()
def test_dig_cells_finds_a_valid_solution(self):
partial_board = self.digger.dig_cells(self.terminal_pattern)
self.assertIsNotNone(partial_board)
self.assertTrue(partial_board.is_valid())
def test_dig_cells_finds_a_unique_solution(self):
partial_board = self.digger.dig_cells(self.terminal_pattern)
self.assertIsNotNone(partial_board)
# For each empty cell in partial_board, try to fill it with a value
# different than the one from terminal_pattern. No solutions should
# yield from this. If any do, then this is not a unique solution.
for i in xrange(9):
for j in xrange(9):
if partial_board.get(i, j) != 0:
# Not an empty cell, move on.
continue
possibilities = partial_board.get_possibilities(i, j)
possibilities.remove(self.terminal_pattern.get(i, j))
for value in possibilities:
partial_board.fill(i, j, value)
self.assertIsNone(solve(partial_board))
# Discard changes.
partial_board.clear(i, j)
def generate_sudoku_with_unique_solution(difficulty):
"""Generates a partially completed sudoku with a unique solution, of the
given difficulty (1 through 5)."""
# Generate a terminal pattern (fully completed sudoku)
terminal_pattern = generate_terminal_pattern()
# Instantiate a Digger instance for the selected difficulty.
digging_strategy = DiggingStrategy(difficulty)
digger = Digger(digging_strategy)
sudoku = digger.dig_cells(terminal_pattern)
return sudoku
