def ucs(current_state, goal_pos, chooseVisited=False):
startpos = current_state.agent.pos
factor = -1 if chooseVisited else 1
# print(startpos, goal_pos)
explored = []
frontier = PriorityQueue()
frontier.push((startpos, []), 0)
while not frontier.isEmpty():
pos, moves = frontier.pop()
if pos == goal_pos:
return moves
explored.append(pos)
for adj, action in GameState.get_adjs(current_state, pos):
if adj not in explored:
newMoves = moves + [action]
frontier.update(
(adj, newMoves),
factor *
getCostOfActions(current_state, startpos, newMoves))
def get_action(self, state):
pos = state.agent.pos
adjs = GameState.get_adjs(state, pos)
self.description = '\n--------------------\nPos: ' + name(pos) + '\n'
self.description += "KB:\t" + str(self.KB.KB) + '\n'
"Moving following by the temporary goals"
if (self.actions != []):
self.description += 'Goal: Move to the next safe place: '
if (self.iLeaving):
self.description += name(state.exit) + ' (Exit)'
else:
self.description += name(self.safe_places[0])
return self.actions.pop(0)
"Gold picking - Prioritize picking gold"
if ('G' in state.explored[pos]):
self.description += 'Goal: Pick gold'
return Actions.PICK_GOLD
"Add KB"
if 'S' in state.explored[pos]:
self.handle_stench(pos, adjs)
"If there is enough condition to conclude the wumpus position"
target_dir, target_pos = self.wumpus_check(pos, adjs)
if (target_dir != None and target_pos not in self.checked_places):
self.checked_places.append(target_pos)
# self.safe_places.append(target_pos)
self.description += 'Goal: Attempting to shoot at ' + \
name(target_pos)
return Actions.shoot(target_dir)
else:
self.handle_not_stench(pos, adjs)
if 'B' in state.explored[pos]:
self.handle_breeze(pos, adjs)
else:
self.handle_not_breeze(pos, adjs)
"Update safe places"
temp = []
for adj, _ in adjs:
if (self.is_safe(adj)
) and adj not in self.visited and adj not in self.safe_places:
temp.append(adj)
self.safe_places.insert(0, adj)
if (temp != []):
self.description += 'Percept: ' + \
str(temp) + ' is safe and not yet visited\n'
"Update visited lists"
self.visited.append(pos)
if (pos in self.safe_places):
self.safe_places.remove(pos)
"Find the next place to move"
if (self.safe_places != []):
self.actions = ucs(state, self.nearest_safe_place())
self.description += 'Goal: Move to the next unvisited safe place: ' + \
name(self.safe_places[0])
return self.actions.pop(0)
"If there is no safe place => Exit"
if pos == state.exit and self.iLeaving:
self.description += 'Goal: Climb out of the cave'
return Actions.EXIT
else:
self.iLeaving = True
self.description += 'Goal: Find the exit to leave'
self.actions = ucs(state, state.exit)
return self.actions.pop(0)
