# your_baseline1.py
# Risk-aware reflex team for CS470 Assignment 3.
from captureAgents import CaptureAgent
import random
import util
from game import Directions
from util import nearestPoint
def createTeam(firstIndex, secondIndex, isRed,
first='RiskAwareOffensiveAgent',
second='PatrolDefensiveAgent'):
return [eval(first)(firstIndex), eval(second)(secondIndex)]
class ReflexCaptureAgent(CaptureAgent):
def registerInitialState(self, gameState):
self.start = gameState.getAgentPosition(self.index)
self.width = gameState.data.layout.width
self.height = gameState.data.layout.height
CaptureAgent.registerInitialState(self, gameState)
self.homeEntries = self.getHomeEntries(gameState)
def chooseAction(self, gameState):
actions = gameState.getLegalActions(self.index)
values = [self.evaluate(gameState, action) for action in actions]
bestValue = max(values)
bestActions = [a for a, v in zip(actions, values) if v == bestValue]
if Directions.STOP in bestActions and len(bestActions) > 1:
bestActions.remove(Directions.STOP)
return random.choice(bestActions)
def getSuccessor(self, gameState, action):
successor = gameState.generateSuccessor(self.index, action)
pos = successor.getAgentState(self.index).getPosition()
if pos != nearestPoint(pos):
return successor.generateSuccessor(self.index, action)
return successor
def evaluate(self, gameState, action):
return self.getFeatures(gameState, action) * self.getWeights(gameState, action)
def getFeatures(self, gameState, action):
features = util.Counter()
successor = self.getSuccessor(gameState, action)
features['successorScore'] = self.getScore(successor)
return features
def getWeights(self, gameState, action):
return {'successorScore': 1.0}
def getHomeEntries(self, gameState):
walls = gameState.getWalls()
if self.red:
x = self.width // 2 - 1
else:
x = self.width // 2
entries = []
for y in range(1, self.height - 1):
if not walls[x][y]:
entries.append((x, y))
return entries or [self.start]
def minDistance(self, pos, targets):
if not pos or not targets:
return 0
return min(self.getMazeDistance(pos, target) for target in targets)
def activeEnemyGhostDistances(self, gameState, myPos):
distances = []
for opponent in self.getOpponents(gameState):
enemy = gameState.getAgentState(opponent)
enemyPos = enemy.getPosition()
if enemyPos is None:
continue
if not enemy.isPacman and enemy.scaredTimer <= 1:
distances.append(self.getMazeDistance(myPos, enemyPos))
return distances
class RiskAwareOffensiveAgent(ReflexCaptureAgent):
def getFeatures(self, gameState, action):
features = util.Counter()
successor = self.getSuccessor(gameState, action)
myState = successor.getAgentState(self.index)
myPos = myState.getPosition()
foodList = self.getFood(successor).asList()
capsules = self.getCapsules(successor)
carrying = myState.numCarrying
ghostDistances = self.activeEnemyGhostDistances(successor, myPos)
closestGhost = min(ghostDistances) if ghostDistances else None
features['successorScore'] = self.getScore(successor)
features['foodRemaining'] = len(foodList)
features['distanceToFood'] = self.minDistance(myPos, foodList)
features['distanceHome'] = self.minDistance(myPos, self.homeEntries)
features['distanceToCapsule'] = self.minDistance(myPos, capsules)
if action == Directions.STOP:
features['stop'] = 1
reverse = Directions.REVERSE[gameState.getAgentState(self.index).configuration.direction]
if action == reverse:
features['reverse'] = 1
if closestGhost is not None:
features['ghostDistance'] = closestGhost
if closestGhost <= 2:
features['immediateDanger'] = 1
elif closestGhost <= 5:
features['nearGhost'] = 1
if carrying >= 3 or len(foodList) <= 2:
features['shouldReturn'] = 1
if carrying > 0 and closestGhost is not None and closestGhost <= 5:
features['shouldReturn'] = 1
if gameState.data.timeleft < features['distanceHome'] + 20:
features['shouldReturn'] = 1
return features
def getWeights(self, gameState, action):
features = self.getFeatures(gameState, action)
weights = {
'successorScore': 200,
'foodRemaining': -100,
'distanceToFood': -3,
'distanceToCapsule': -2,
'ghostDistance': 2,
'immediateDanger': -1000,
'nearGhost': -180,
'stop': -100,
'reverse': -3,
'shouldReturn': 0,
'distanceHome': 0,
}
if features['shouldReturn']:
weights['distanceHome'] = -15
weights['distanceToFood'] = -1
weights['distanceToCapsule'] = -1
if features['nearGhost'] or features['immediateDanger']:
weights['distanceToCapsule'] = -8
return weights
class PatrolDefensiveAgent(ReflexCaptureAgent):
def registerInitialState(self, gameState):
ReflexCaptureAgent.registerInitialState(self, gameState)
self.patrolTarget = self.choosePatrolTarget(gameState)
self.lastEatenFood = None
def chooseAction(self, gameState):
self.updateLastEatenFood(gameState)
invaders = self.visibleInvaders(gameState)
if invaders:
self.patrolTarget = min(
[a.getPosition() for a in invaders],
key=lambda p: self.getMazeDistance(gameState.getAgentPosition(self.index), p)
)
elif self.lastEatenFood is not None:
self.patrolTarget = self.lastEatenFood
elif self.patrolTarget is None:
self.patrolTarget = self.choosePatrolTarget(gameState)
return ReflexCaptureAgent.chooseAction(self, gameState)
def getFeatures(self, gameState, action):
features = util.Counter()
successor = self.getSuccessor(gameState, action)
myState = successor.getAgentState(self.index)
myPos = myState.getPosition()
invaders = self.visibleInvaders(successor)
features['onDefense'] = 1
if myState.isPacman:
features['onDefense'] = 0
features['numInvaders'] = len(invaders)
if invaders:
features['invaderDistance'] = min(
self.getMazeDistance(myPos, invader.getPosition()) for invader in invaders
)
else:
features['distanceToPatrol'] = self.getMazeDistance(myPos, self.patrolTarget)
if action == Directions.STOP:
features['stop'] = 1
reverse = Directions.REVERSE[gameState.getAgentState(self.index).configuration.direction]
if action == reverse:
features['reverse'] = 1
return features
def getWeights(self, gameState, action):
return {
'numInvaders': -1000,
'onDefense': 120,
'invaderDistance': -20,
'distanceToPatrol': -4,
'stop': -100,
'reverse': -2,
}
def visibleInvaders(self, gameState):
enemies = [gameState.getAgentState(i) for i in self.getOpponents(gameState)]
return [enemy for enemy in enemies if enemy.isPacman and enemy.getPosition() is not None]
def updateLastEatenFood(self, gameState):
previous = self.getPreviousObservation()
if previous is None:
return
previousFood = set(self.getFoodYouAreDefending(previous).asList())
currentFood = set(self.getFoodYouAreDefending(gameState).asList())
eaten = list(previousFood - currentFood)
if eaten:
myPos = gameState.getAgentPosition(self.index)
self.lastEatenFood = min(eaten, key=lambda p: self.getMazeDistance(myPos, p))
def choosePatrolTarget(self, gameState):
defendingFood = self.getFoodYouAreDefending(gameState).asList()
if not defendingFood:
return random.choice(self.homeEntries)
foodCenter = (
sum(x for x, y in defendingFood) / float(len(defendingFood)),
sum(y for x, y in defendingFood) / float(len(defendingFood))
)
return min(
self.homeEntries,
key=lambda p: abs(p[0] - foodCenter[0]) + abs(p[1] - foodCenter[1])
)