def longest_path_to(self, des):
"""Find the longest path from the snake's head to the destination.
Args:
des (snake.base.pos.Pos): The destination position on the map.
Returns:
A collections.deque of snake.base.direc.Direc indicating the path directions.
"""
path = self.shortest_path_to(des)
if not path:
return deque()
self._reset_table()
cur = head = self.snake.head()
# Set all positions on the shortest path to 'visited'
self._table[cur.x][cur.y].visit = True
for direc in path:
cur = cur.adj(direc)
self._table[cur.x][cur.y].visit = True
# Extend the path between each pair of the positions
idx, cur = 0, head
while True:
cur_direc = path[idx]
nxt = cur.adj(cur_direc)
if cur_direc == Direc.LEFT or cur_direc == Direc.RIGHT:
tests = [Direc.UP, Direc.DOWN]
elif cur_direc == Direc.UP or cur_direc == Direc.DOWN:
tests = [Direc.LEFT, Direc.RIGHT]
extended = False
for test_direc in tests:
cur_test = cur.adj(test_direc)
nxt_test = nxt.adj(test_direc)
if self._is_valid(cur_test) and self._is_valid(nxt_test):
self._table[cur_test.x][cur_test.y].visit = True
self._table[nxt_test.x][nxt_test.y].visit = True
path.insert(idx, test_direc)
path.insert(idx + 2, Direc.opposite(test_direc))
extended = True
break
if not extended:
cur = nxt
idx += 1
if idx >= len(path):
break
return path
def longest_path_to(self, des):
"""Find the longest path from the snake's head to the destination.
Args:
des (snake.base.pos.Pos): The destination position on the map.
Returns:
A collections.deque of snake.base.direc.Direc indicating the path directions.
"""
path = self.shortest_path_to(des)
if not path:
return deque()
self._reset_table()
cur = head = self.snake.head()
# Set all positions on the shortest path to 'visited'
self._table[cur.x][cur.y].visit = True
for direc in path:
cur = cur.adj(direc)
self._table[cur.x][cur.y].visit = True
# Extend the path between each pair of the positions
idx, cur = 0, head
while True:
cur_direc = path[idx]
nxt = cur.adj(cur_direc)
if cur_direc == Direc.LEFT or cur_direc == Direc.RIGHT:
tests = [Direc.UP, Direc.DOWN]
elif cur_direc == Direc.UP or cur_direc == Direc.DOWN:
tests = [Direc.LEFT, Direc.RIGHT]
extended = False
for test_direc in tests:
cur_test = cur.adj(test_direc)
nxt_test = nxt.adj(test_direc)
if self._is_valid(cur_test) and self._is_valid(nxt_test):
self._table[cur_test.x][cur_test.y].visit = True
self._table[nxt_test.x][nxt_test.y].visit = True
path.insert(idx, test_direc)
path.insert(idx + 2, Direc.opposite(test_direc))
extended = True
break
if not extended:
cur = nxt
idx += 1
if idx >= len(path):
break
return path
def _choose_action(self, e_greedy=True):
action_idx = None
if e_greedy and np.random.uniform() < self._epsilon:
while True:
action_idx = np.random.randint(0, self._NUM_ACTIONS)
if Direc.opposite(
self.snake.direc) != self._SNAKE_ACTIONS[action_idx]:
break
else:
q_eval_all = self._sess.run(
self._q_eval_all,
feed_dict={self._state_eval: self._state()[np.newaxis, :]})
q_eval_all = q_eval_all[0]
# Find indices of actions with 1st and 2nd largest q value
action_indices = np.argpartition(q_eval_all, q_eval_all.size - 2)
action_idx = action_indices[-1]
# If opposite direction, return direction with 2nd largest q value
if Direc.opposite(
self.snake.direc) == self._SNAKE_ACTIONS[action_idx]:
action_idx = action_indices[-2]
return action_idx
def _choose_action(self, e_greedy=True):
action_idx = None
if e_greedy and np.random.uniform() < self._epsilon:
while True:
action_idx = np.random.randint(0, self._NUM_ACTIONS)
if Direc.opposite(self.snake.direc) != self._SNAKE_ACTIONS[action_idx]:
break
else:
q_eval_all = self._sess.run(
self._q_eval_all,
feed_dict={
self._state_eval: self._state()[np.newaxis, :]
}
)
q_eval_all = q_eval_all[0]
# Find indices of actions with 1st and 2nd largest q value
action_indices = np.argpartition(q_eval_all, q_eval_all.size - 2)
action_idx = action_indices[-1]
# If opposite direction, return direction with 2nd largest q value
if Direc.opposite(self.snake.direc) == self._SNAKE_ACTIONS[action_idx]:
action_idx = action_indices[-2]
return action_idx
def __update_direc(self, new_direc):
if Direc.opposite(new_direc) != self.__snake.direc:
self.__snake.direc_next = new_direc
if self.__pause:
self.__snake.move()
def test_opposite():
assert Direc.opposite(Direc.UP) == Direc.DOWN
assert Direc.opposite(Direc.DOWN) == Direc.UP
assert Direc.opposite(Direc.LEFT) == Direc.RIGHT
assert Direc.opposite(Direc.RIGHT) == Direc.LEFT