def is_point_an_eye(board, point, color):
#if stone is at point, then point cant be an eye
if board.get(point) is not None:
return False
#all adjacent stones must contain friendly stones
for neighbor in point.neighbors():
if board.is_on_grid(neighbor):
neighbor_color = board.get(neighbor)
if neighbor != color:
return False
#must control 3 out of 4 corners if the point is in middle of board,
#while on the edge of the board must control 4 corners
friendly_corners = 0
off_board_corners = 0
corners = [
Point(point.row - 1, point.col - 1),
Point(point.row - 1, point.col + 1),
Point(point.row + 1, point.col - 1),
Point(point.row + 1, point.col + 1),
]
for corner in corners:
if board.is_on_grid(corner):
corner_color = board.get(corner)
if corner_color == color:
friendly_corners += 1
else:
off_board_corners += 1
if off_board_corners > 0:
#point is on edge or corner
return off_board_corners + friendly_cornes == 4
#point is in middle
return friendly_corners >= 3
def select_move(self, game_state):
"""Choose a random valid move that preserves our own eyes."""
candidates = []
for r in range(1, game_state.board.num_rows + 1):
for c in range(1, game_state.board.num_cols + 1):
candidate = Point(row=r, col=c)
if game_state.is_valid_move(Move.play(candidate)) and \
not is_point_an_eye(game_state.board,
candidate,
game_state.next_player):
candidates.append(candidate)
if not candidates:
return Move.pass_turn()
print(Move.play(random.choice(candidates)))
# end::random_bot[]
def legal_moves(self):
"using this bypasses the need of is_valid_move"
moves = []
for row in range(1, self.board.num_rows + 1):
for col in range(1, self.board.num_cols + 1):
move = Move.play(Point(row, col))
if self.is_valid_move(move):
moves.append(move)
moves.append(Move.pass_turn())
moves.append(Move.resign())
return moves
def select_move(self, game_state):
"""Selects random value that preserves eyes"""
candidates = []
for r in range(1, game_state.board.num_rows + 1):
for c in range(1, game_state.board.num_cols + 1):
candidate = Point(
row=r,
col=c) #added first parameter to Move.play below to be "1"
if game_state.is_valid_move(Move.play(candidate)) and \
not is_point_an_eye(game_state.board, \
candidate, \
game_state.next_player):
candidates.append(candidate)
if not candidates:
return Move.pass_turn()
return Move.play(random.choice(candidates))
def evaluate_territory(board):
status = {}
for r in range(1, board.num_cols + 1):
for c in range(1, board.num_cols+ 1):
p = Point(row=r, col=c)
if p in status:
continue
stone = board.get(p)
if stone is not None:
status[p] = board.get(p)
else:
group, neighbors = _collect_region(p, board)
if len(neighbors) == 1:
neighbor_stone = neighbors.pop()
stone_str = 'b' if neighbor_stone == Player.black else 'w'
fill_with = 'territory_' + stone_str
else:
fill_with = 'dame'
for pos in group:
status[pos] = fill_with
return Territory(status)
def _collect_region(start_pos, board, visited=None):
if visited is None:
visited = {}
if start_pos in visited:
return [], set()
all_points = [start_pos]
all_borders = set()
visited[start_pos] = True
here = board.get(start_pos)
deltas = [(-1,0), (1,0), (0,-1), (0,1)]
for delta_r, delta_c in deltas:
next_p = Point(row=start_pos.row + delta_r, col=start_pos.col + delta_c)
if not board.is_on_grid(next_p):
continue
neighbor = board.get(next_p)
if neighbor == here:
points, borders = _collect_region(next_p, board, visited)
all_points += points
all_borders |= borders
else:
all_borders.add(neighbor)
return all_points, all_borders
def is_point_an_eye(board, point, color):
if board.get(point) is not None: # <1>
return False
for neighbor in point.neighbors(): # <2>
if board.is_on_grid(neighbor):
neighbor_color = board.get(neighbor)
if neighbor_color != color:
return False
friendly_corners = 0 # <3>
off_board_corners = 0
corners = [
Point(point.row - 1, point.col - 1),
Point(point.row - 1, point.col + 1),
Point(point.row + 1, point.col - 1),
Point(point.row + 1, point.col + 1),
]
for corner in corners:
if board.is_on_grid(corner):
corner_color = board.get(corner)
if corner_color == color:
friendly_corners += 1
else:
off_board_corners += 1
if off_board_corners > 0:
return off_board_corners + friendly_corners == 4 # <4>
return friendly_corners >= 3 # <5>
# <1> An eye is an empty point.
# <2> All adjacent points must contain friendly stones.
# <3> We must control 3 out of 4 corners if the point is in the middle of the board; on the edge we must control all corners.
# <4> Point is on the edge or corner.
# <5> Point is in the middle.
# end::eye[]