def test_queen_attacks(self):
queen = create_piece('q', 0, 0)
for i in range(1, 8):
self.assertTrue(queen.is_attacking_position(i, i))
self.assertTrue(queen.is_attacking_position(i, 0))
self.assertTrue(queen.is_attacking_position(0, i))
self.assertFalse(queen.is_attacking_position(i, i + 1))
def place_pieces(board_list, board, pieces, index=0, offset=0):
"""
Backtracking algorithm to place a list of pieces in the board.
:param board_list: list of found boards
:param board: current board
:param pieces: list of pieces
:param index: current piece index
:param offset: current starting offset
:return:
"""
if index == len(pieces):
board_list.append(board)
else:
current_offset = offset
piece = create_piece(pieces[index])
while current_offset < (board.rows * board.columns):
try:
used_offset = board.place_piece(piece, current_offset)
except ValueError:
break
place_pieces(board_list, copy.deepcopy(board), pieces, index + 1,
used_offset + 1)
board.remove_piece(piece)
current_offset = used_offset + 1
def place_piece(self, piece, offset):
"""
Place a piece in the next available position starting from the offset.
"""
if offset >= self.rows * self.columns:
raise ValueError("Out of Bounds")
for next_offset in range(offset, self.rows * self.columns):
row, column = self.get_row_column(next_offset)
if self.is_safe(create_piece(piece.name, row, column)):
piece.row, piece.column = row, column
self.pieces.append(piece)
return next_offset
raise ValueError("Out of Bounds")
def test_create_pieces(self):
self.assertEqual(create_piece('k'), King())
self.assertEqual(create_piece('q'), Queen())
self.assertEqual(create_piece('b'), Bishop())
self.assertEqual(create_piece('r'), Rook())
self.assertEqual(create_piece('n'), Knight())
def test_knight_attacks(self):
knight = create_piece('n', 0, 0)
self.assertTrue(knight.is_attacking_position(1, 2))
self.assertTrue(knight.is_attacking_position(2, 1))
self.assertFalse(knight.is_attacking_position(1, 1))
def test_bishop_attacks(self):
bishop = create_piece('b', 0, 0)
for i in range(1, 8):
self.assertTrue(bishop.is_attacking_position(i, i))
self.assertFalse(bishop.is_attacking_position(0, i))
def test_rook_attacks(self):
rook = create_piece('r', 0, 0)
for i in range(1, 8):
self.assertTrue(rook.is_attacking_position(0, i))
self.assertTrue(rook.is_attacking_position(i, 0))
self.assertFalse(rook.is_attacking_position(i, i))
def test_king_attacks(self):
king = create_piece('k', 0, 0)
self.assertTrue(king.is_attacking_position(1, 1))
self.assertFalse(king.is_attacking_position(2, 2))
def test_is_safe(self):
k1 = create_piece('k')
q1 = create_piece('q', 1, 2)
board = Board(3, 3)
board.place_piece(k1, 0)
self.assertTrue(board.is_safe(q1))
def test_place_pieces(self):
k1 = create_piece('k')
k2 = create_piece('k')
board = Board(3, 3)
self.assertEqual(board.place_piece(k1, 0), 0)
self.assertEqual(board.place_piece(k2, 0), 2)