def _step(self, board: Board) -> Board:
"""
Performs one hill climb step
:param board: Current state of the board to step from
:return: Board after the step
"""
# select random line from unfilled ones
unfilled = board.unfilled_by_row()
row = list(unfilled.keys())[random.randint(0, len(unfilled) - 1)]
line = board.values()[row]
# swap 2 characters in it
self._swap_in_line(line, unfilled[row])
# update original board
board.fill_line(row, line)
return board
def _beta_operator(self, board: Board):
"""
ß-operator of the ß-climbing, introduces exploration to the algorithm
:param board: Neighbouring state of the board
:return: New state of the board
"""
# go through modifiable rows
unfilled = board.unfilled_by_row()
for row in unfilled:
# regenerate the row with probability of beta
if self._with_probability(self._beta_prob):
line = board.values()[row]
# clear
for index in unfilled[row]:
line[index] = 0
# refill
board.fill_line(row, np.array(self._fill_line_unique(line)))
return board
