def max(self, state, a, b, table):
util = -999
possActs = state.actions()
best = None
#if state in table:
# return best;
#else:
#checks if the current state is terminal
if (state.is_terminal()):
return state.utility(currPly)
#if there are no possible actions with this board
if not (possActs):
#set the next state to be the same board,
#but with the opponents row
nextState = State(state.board, state.opponent_row, state.player)
#and run it
util = self.min(nextState, a, b, table)
if (util >= b):
return util
if (util > a):
a = util
#if theres no already best set action
if best is None:
#if there are possible actions
while (possActs):
#get the next possible action
curr = possActs.pop(0)
#get the state that results from the current action
nextState = state.result(curr)
#get the utility
nextUtil = self.min(nextState, a, b, table)
#if the utility is greater reassign the current utility
#and add the move a the current best move into the table
if (nextUtil > util):
util = nextUtil
best = curr
table[state.ser] = (best, util)
#compare the utility with alpha and beta
if (util >= b):
return util
elif (util > a):
a = util
#return the utility
return util
def minmax(self, state, num): #starts off by getting all possible actions posActs=state.actions() global action if (state.is_terminal()): table[state.ser] = None return state.utility(currPly) #checks if the game reached a terminal state #and if it did it return the utility #sets the util based on current player if(currPly.row == state.player_row): util =-1; else: util =1; #if there are no possible actions available if not(posActs): nextState = State(state.board, state.opponent_row, state.player) util = self.minmax(nextState, False) table[state.ser] = None return util while(posActs): currentAction =posActs.pop() nextState = state.result(currentAction) nextUtility = self.minmax(nextState, False) if (currPly.row == state.player_row): if (util <= nextUtility): util = nextUtility; table[state.ser] = currentAction else: if (util >= nextUtility): util = nextUtility table[state.ser] = currentAction return util
def minValue(self, state, depth):
global transpositionTable
''' state key '''
'''
stateString = ""
for i in state.board:
stateString += str(i)
stateString += ","
stateString += str(state.player_row)
'''
stateString = state.ser()
''' 1. Terminal test '''
if (state.is_terminal()):
utility = state.utility(player)
transpositionTable[stateString] = (None, utility)
return utility
''' 2. Initialize utility to positive infinite (effectively) '''
utility = 2
''' Process actions '''
actions = state.actions()
# No actions available
if not (actions):
nextState = State(state.board, state.opponent_row, state.player)
utility = self.maxValue(nextState, depth + 1)
transpositionTable[stateString] = (None, utility)
return utility
else:
while (actions):
currentAction = actions.pop(0)
nextState = state.result(currentAction)
utilityTmp = self.maxValue(nextState, depth + 1)
# Get the max utility
if (utility > utilityTmp):
utility = utilityTmp
transpositionTable[stateString] = (currentAction, utility)
return utility
def min(self, state, a, b, table):
best = None
util = 999
possActs = state.actions()
if (state.is_terminal()):
return state.utility(currPly)
#if state in table:
# return best;
#else:
if not (possActs):
nextState = State(state.board, state.opponent_row, state.player)
util = self.max(nextState, a, b, table)
if (util <= a):
return util
if (b > util):
b = util
if best is None:
while (possActs):
curr = possActs.pop(0)
nextState = state.result(curr)
nextUtil = self.max(nextState, a, b, table)
if (util > nextUtil):
util = nextUtil
best = curr
table[state.ser] = (best, util)
if (util <= a):
return util
if (util < b):
b = util
return util
def maxValue(self, state, alpha, beta, depth):
global depth_limit
global transpositionTableForMax
global search_is_complete
global max_depth_reached
if (depth >= max_depth_reached):
max_depth_reached = depth
''' state key '''
'''
stateString = ""
for i in state.board:
stateString += str(i)
stateString += ","
'''
stateString = state.ser()
''' Check the time '''
if (self.is_time_up()):
if (state.is_terminal()):
value = state.utility(player)
else:
value = self.evaluate(state, player.row, depth)
search_is_complete = False
#transpositionTableForMax[stateString] = (None, value, depth)
return value
''' Check the depth '''
if (depth >= depth_limit):
if (state.is_terminal()):
value = state.utility(player)
else:
value = self.evaluate(state, player.row, depth)
search_is_complete = False
#transpositionTableForMax[stateString] = (None, value, depth)
return value
''' PROCEED NORMALLY FROM HERE '''
''' 1. Terminal test '''
if (state.is_terminal()):
value = state.utility(player)
#transpositionTableForMax[stateString] = (None, value, depth)
return value
''' 2. Initialize value to negative infinite (effectively) '''
value = -2
''' Process actions '''
actions = state.actions()
# No actions available
if not (actions):
nextState = State(state.board, state.opponent_row, state.player)
value = self.minValue(nextState, alpha, beta, depth + 1)
#transpositionTableForMax[stateString] = (None, value, depth)
# Prune if possible
'''
if (value >= beta):
print "PRUNING WHEN THERE's NO ACTION"
return value
'''
'''
if (value > alpha):
alpha = value
'''
return value
else:
bestAction = transpositionTableForMax.get(stateString, None)
if not (bestAction is None):
currentAction = bestAction[0]
#print "BEST ACTION AT MAX" + stateString + " " + str(currentAction.index)
#print str(state.board)
nextState = state.result(currentAction)
valueTmp = self.minValue(nextState, alpha, beta, depth + 1)
# Get the max value
if (value < valueTmp):
value = valueTmp
#print "Storing for max, at " + stateString + " " + str(currentAction.index)
transpositionTableForMax[stateString] = (currentAction,
value, depth)
# Prune if possible
if (value >= beta):
return value
if (value > alpha):
alpha = value
while (actions):
currentAction = actions.pop(0)
if not (currentAction == bestAction[0]):
nextState = state.result(currentAction)
valueTmp = self.minValue(nextState, alpha, beta,
depth + 1)
#if (depth == 0):
# print str(nextState.board) + " " + str(valueTmp)
# Get the max value
if (value < valueTmp):
value = valueTmp
#print "Storing for max, at " + stateString + " " + str(currentAction.index)
transpositionTableForMax[stateString] = (
currentAction, value, depth)
# TIEBREAKER
if (value == valueTmp):
if (currentAction.index < (bestAction[0]).index):
transpositionTableForMax[stateString] = (
currentAction, value, depth)
# Prune if possible
if (value > beta):
return value
if (value > alpha):
alpha = value
else:
while (actions):
currentAction = actions.pop(0)
nextState = state.result(currentAction)
valueTmp = self.minValue(nextState, alpha, beta, depth + 1)
#if (depth == 0):
# print str(nextState.board) + " " + str(valueTmp)
# Get the max value
if (value < valueTmp):
value = valueTmp
#print "Storing for max, at " + stateString + " " + str(currentAction.index)
transpositionTableForMax[stateString] = (currentAction,
value, depth)
# Prune if possible
if (value >= beta):
return value
if (value > alpha):
alpha = value
return value
def __init__(self, M, N, K, player_classes, timeout=None):
self.players = Player.create_players(player_classes)
self.state = State.initial(M, N, K, self.players[0])
self.timeout = timeout
def maxValue(self, state, alpha, beta, depth):
#print "maxValue executes at depth " + str(depth)
stateString = ""
for i in state.board:
stateString += str(i)
stateString += str(state.player_row)
#print stateString
global changed
#print("MAX VALUE CALLED")
global depth_limit
# Check the time, start exiting
if (self.is_time_up == True):
print("TIME IS UP")
return self.evaluate(state, state.player_row)
#print("TIME IS NOT UP")
# Check the depth:
if (depth >= depth_limit):
#print ("REACHED THE LIMIT")
return self.evaluate(state, state.player_row)
#print ("PAST THE CHECK")
# Check if best action exists
bestAction = transposition_table.get(stateString, None)
value = (state.M * state.N + 1) * -1
if (stateString == "020700180"):
print str(value) + " BWAEfORE"
# Best Action Exists
# Expand best node first
if not (bestAction is None):
# Terminal test, exit
if (state.is_terminal()):
return bestAction[1]
nextState = state.result(bestAction[0])
valueTmp = self.minValue(nextState, alpha, beta, depth + 1)
# Update value
if (value > valueTmp):
value = valueTmp
# Prune if able to
if (value >= beta):
return value
# Update alpha
if (value > alpha):
alpha = value
'''
# Terminal test
if (state.is_terminal()):
return state.utility(player)
# Past lowest possible utility, effectively negative infinite
utility = 2
'''
else:
### Change best action ###
print "MAX" + stateString
changed = True
# Terminal test, exit
if (state.is_terminal()):
#print ("TERMINAL STATE")
value = self.evaluate(state, state.player_row)
transposition_table[stateString] = (None, value)
return self.evaluate(state, state.player_row)
# Then expand OTHER nodes
# Get the actions from this state
actions = state.actions()
# No available actions, repeat state but switch players
if not (actions):
#print "NO ACTIONS FOR MAX"
nextState = State(state.board, state.opponent_row, state.player)
value = self.minValue(nextState, alpha, beta, depth + 1)
transposition_table[stateString] = (None, value)
if (value >= beta):
return value
if (value > alpha):
alpha = value
# Actions available
if (stateString == "020700180"):
print str(value) + " BEfORE"
while (actions):
currentAction = actions.pop(0)
# Check only nodes that aren't the previous best action
if not (bestAction == None):
if not (currentAction == bestAction[0]):
nextState = state.result(currentAction)
valueTmp = self.minValue(nextState, alpha, beta, depth + 1)
if (valueTmp > value):
value = valueTmp
newBestAction = currentAction
#if (stateString == "1011101"):
# print "WHAT?"
transposition_table[stateString] = (newBestAction,
value)
# tie break
'''
if (utility == utilityTmp):
bestAction = alphabetatranspositionTable.get(stateString, None)
index = bestAction[0].index
if (currentAction.index < index):
print "tiebreaking"
bestAction = currentAction
alphabetatranspositionTable[stateString] = (bestAction, utility)'''
# Prune if able
if (value >= beta):
return value
# Update alpha
if (value > alpha):
alpha = value
else:
#print "NO BEST ACTION CHECKING ALL from " + stateString + " with intial value: " + str(value)
nextState = state.result(currentAction)
valueTmp = self.minValue(nextState, alpha, beta, depth + 1)
print str(value)
if (valueTmp > value):
if (stateString == "020700180"):
print "ACTION available"
value = valueTmp
newBestAction = currentAction
transposition_table[stateString] = (newBestAction, value)
# tie break
'''
if (utility == utilityTmp):
bestAction = alphabetatranspositionTable.get(stateString, None)
index = bestAction[0].index
if (currentAction.index < index):
print "tiebreaking"
bestAction = currentAction
alphabetatranspositionTable[stateString] = (bestAction, utility)'''
# Prune if able
if (value >= beta):
return value
# Update alpha
if (value > alpha):
alpha = value
return value
def minValue(self, state, alpha, beta, depth):
#print "minValue executes at depth " + str(depth)
stateString = ""
for i in state.board:
stateString += str(i)
stateString += str(state.player_row)
#print stateString
global changed
global depth_limit
#print "MIN VALUE VALLED"
# Check the time, start exiting
if (self.is_time_up == True):
print "TIME US UP"
return self.evaluate(state, state.player_row)
#print "TIME US NOT UP"
'''
# Terminal test, exit
if (state.is_terminal()):
#print "TERMINAL"
return self.evaluate(state, state.player_row) * -1
'''
# Check the depth:
if (depth >= depth_limit):
#print self.evaluate(state, state.player_row) * -1
return self.evaluate(state, state.player_row)
# Check if best action exists
bestAction = transposition_table.get(stateString, None)
value = state.M * state.N + 1
# Best Action Exists
# Expand best node first
if not (bestAction is None):
#print "best action exists"
# Terminal test, exit
if (state.is_terminal()):
return bestAction[1]
nextState = state.result(bestAction[0])
valueTmp = self.maxValue(nextState, alpha, beta, depth + 1)
# Update value
if (value > valueTmp):
value = valueTmp
# Prune if able to
if (value <= alpha):
return value
# Update beta
if (value < beta):
beta = value
'''
# Terminal test
if (state.is_terminal()):
return state.utility(player)
# Past lowest possible utility, effectively negative infinite
utility = 2
'''
else:
#print "best action does not exist"
### Change best action ###
print stateString
changed = True
#print "must print"
# Terminal test, exit
if (state.is_terminal()):
#print (stateString + "TERMINAL STATE")
value = self.evaluate(state, state.player_row)
transposition_table[stateString] = (None, value)
return self.evaluate(state, state.player_row)
# Then expand OTHER nodes
# Get the actions from this state
actions = state.actions()
# No available actions, repeat state but switch players
if not (actions):
#print "NO ACTIONS FOR MIN"
nextState = State(state.board, state.opponent_row, state.player)
value = self.maxValue(nextState, alpha, beta, depth + 1)
transposition_table[stateString] = (None, value)
if (value <= alpha):
return value
if (value < beta):
beta = value
# Actions available
while (actions):
currentAction = actions.pop(0)
if not (bestAction == None):
# Check only nodes that aren't the previous best action
if not (currentAction == bestAction[0]):
nextState = state.result(currentAction)
valueTmp = self.maxValue(nextState, alpha, beta, depth + 1)
if (value > valueTmp):
value = valueTmp
newBestAction = currentAction
transposition_table[stateString] = (newBestAction,
value)
# tie break
'''
if (utility == utilityTmp):
bestAction = alphabetatranspositionTable.get(stateString, None)
index = bestAction[0].index
if (currentAction.index < index):
print "tiebreaking"
bestAction = currentAction
alphabetatranspositionTable[stateString] = (bestAction, utility)'''
# Prune if able
if (value <= alpha):
return value
# Update beta
if (value < beta):
beta = value
else:
nextState = state.result(currentAction)
valueTmp = self.maxValue(nextState, alpha, beta, depth + 1)
if (value > valueTmp):
value = valueTmp
newBestAction = currentAction
transposition_table[stateString] = (newBestAction, value)
# tie break
'''
if (utility == utilityTmp):
bestAction = alphabetatranspositionTable.get(stateString, None)
index = bestAction[0].index
if (currentAction.index < index):
print "tiebreaking"
bestAction = currentAction
alphabetatranspositionTable[stateString] = (bestAction, utility)'''
# Prune if able
if (value <= alpha):
return value
# Update beta
if (value < beta):
beta = value
return value
def __init__(self, M, N, K, player_classes, timeout=None):
self.players = Player.create_players(player_classes)
self.state = State.initial(M, N, K, self.players[0])
self.timeout = timeout
def maxValue(self, state, alpha, beta, depth):
global transpositionTableForMax
''' state key '''
'''
stateString = ""
for i in state.board:
stateString += str(i)
stateString += ","
'''
stateString = state.ser()
''' Check to see if we've already encountered this state '''
'''
action = transpositionTableForMax.get(stateString, None)
if not(action is None):
return action[1]
'''
''' 1. Terminal test '''
if (state.is_terminal()):
utility = state.utility(player)
#transpositionTableForMax[stateString] = (None, utility, depth)
return utility
''' 2. Initialize utility to negative infinite (effectively) '''
utility = -2
''' Process actions '''
actions = state.actions()
# No actions available
if not (actions):
nextState = State(state.board, state.opponent_row, state.player)
utility = self.minValue(nextState, alpha, beta, depth + 1)
#transpositionTableForMax[stateString] = (None, utility, depth)
# Prune if possible
'''
if (utility >= beta):
print "PRUNING WHEN THERE's NO ACTION"
return utility
'''
'''
if (utility > alpha):
alpha = utility
'''
return utility
else:
bestAction = transpositionTableForMax.get(stateString, None)
if not (bestAction is None):
currentAction = bestAction[0]
nextState = state.result(currentAction)
utilityTmp = self.minValue(nextState, alpha, beta, depth + 1)
# Get the max utility
if (utility < utilityTmp):
utility = utilityTmp
transpositionTableForMax[stateString] = (currentAction,
utility, depth)
# Prune if possible
if (utility >= beta):
return utility
if (utility > alpha):
alpha = utility
while (actions):
currentAction = actions.pop(0)
if not (currentAction == bestAction[0]):
nextState = state.result(currentAction)
utilityTmp = self.minValue(nextState, alpha, beta,
depth + 1)
# Get the max utility
if (utility < utilityTmp):
utility = utilityTmp
transpositionTableForMax[stateString] = (
currentAction, utility, depth)
# Prune if possible
if (utility >= beta):
return utility
if (utility > alpha):
alpha = utility
else:
while (actions):
currentAction = actions.pop(0)
nextState = state.result(currentAction)
utilityTmp = self.minValue(nextState, alpha, beta,
depth + 1)
# Get the max utility
if (utility < utilityTmp):
utility = utilityTmp
transpositionTableForMax[stateString] = (currentAction,
utility,
depth)
# Prune if possible
if (utility > beta):
return utility
if (utility > alpha):
alpha = utility
return utility
def minimax(self, state, first):
global action
actionIndex = state.M * 2 + 2
actions = state.actions()
# Reached terminal state
if (state.is_terminal()):
# Return the state's utility
utility = state.utility(player)
#print "TERMINAL " + str(state.board) + " " + str(utility)
return utility
# max
if (state.player_row == player.row):
utility = -2
if not (actions):
# no actions available
nextState = State(state.board, state.opponent_row,
state.player)
utility = self.minimax(nextState, first + 1)
bestAction = None
while (actions):
currentAction = actions.pop(0)
nextState = state.result(currentAction)
utilityTmp = self.minimax(nextState, first + 1)
if (utility <= utilityTmp):
utility = utilityTmp
# first move
if (first == 1):
action = currentAction
actionIndex = currentAction.index
# first move
'''
if (utility == utilityTmp):
if (first == 1):
if (currentAction.index < actionIndex):
print "tiebreaking"
action = currentAction
actionIndex = currentAction.index'''
# min
if (state.player_row != player.row):
utility = 2
if not (actions):
# no actions available
nextState = State(state.board, state.opponent_row,
state.player)
utility = self.minimax(nextState, first + 1)
while (actions):
currentAction = actions.pop(0)
nextState = state.result(currentAction)
utilityTmp = self.minimax(nextState, first + 1)
if (utility > utilityTmp):
utility = utilityTmp
# first move
if (first == 1):
action = currentAction
actionIndex = currentAction.index
return utility
def maxValue(self, state, alpha, beta, depth):
'''
global maxDepth
if depth > maxDepth:
maxDepth = depth
'''
stateString = ""
for i in state.board:
stateString += str(i)
stateString += str(state.player_row)
bestAction = alphabetatranspositionTable.get(stateString, None)
if bestAction is None:
# Terminal test
if (state.is_terminal()):
utility = state.utility(player)
print "TERMINAL " + stateString + " " + str(utility)
alphabetatranspositionTable[stateString] = (None, utility,
depth)
return utility
# Past lowest possible utility, effectively negative infinite
utility = -2
# Get the actions from this state
actions = state.actions()
# No available actions, repeat state but switch players
if not (actions):
nextState = State(state.board, state.opponent_row,
state.player)
utility = self.minValue(nextState, alpha, beta, depth + 1)
alphabetatranspositionTable[stateString] = (None, utility,
depth)
if (utility >= beta):
return utility
if (utility > alpha):
alpha = utility
# Actions available
while (actions):
currentAction = actions.pop(0)
nextState = state.result(currentAction)
utilityTmp = self.minValue(nextState, alpha, beta, depth + 1)
if (depth == 0):
print str(nextState.board) + " " + str(utilityTmp)
if (utility < utilityTmp):
utility = utilityTmp
bestAction = currentAction
alphabetatranspositionTable[stateString] = (bestAction,
utility, depth)
if (utility >= beta):
return utility
if (utility > alpha):
alpha = utility
return utility
else:
return bestAction[1]
def maxValue(self, state, alpha, beta, depth):
global maxDepth
if (depth > maxDepth):
maxDepth = depth
global nonTerminal
stateString = ""
for i in state.board:
stateString += str(i)
stateString += str(state.player_row)
#if (stateString == "11110111100"):
#if not(transposition_table):
#print "GOOD"
#if (depth_limit == 35 or depth_limit == 36):
#print stateString
# If we're at the depth limit, stop
# Apply utility function if we're at terminal node, apply evaluation function if we're not
if (depth >= depth_limit):
# Terminal test
if (state.is_terminal()):
#print "Applying utility"
utility = state.utility(player)
"Applying utility for " + stateString + " " + str(utility)
transposition_table[stateString] = (None, utility, depth)
return utility
else:
#print "Applying evaluation"
#changed = True
value = self.evaluate(state, player.row)
"Applying valuefor " + stateString + " " + str(value)
transposition_table[stateString] = (None, value, depth)
nonTerminal = True
return value
# We're not at the depth limit, handle terminality anyways
# Terminal test
if (state.is_terminal()):
utility = state.utility(player)
"Applying utility not at depth limit for " + stateString + " " + str(
utility)
transposition_table[stateString] = (None, utility, depth)
return utility
# Otherwise we expand the node
# Past lowest possible utility, effectively negative infinite
utility = -2
# Get the actions from this state
actions = state.actions()
# No best action yet, will be set recursively on the way up
bestAction = None
# No available actions, repeat state but switch players
if not (actions):
nextState = State(state.board, state.opponent_row, state.player)
utility = self.minValue(nextState, alpha, beta, depth + 1)
transposition_table[stateString] = (None, utility, depth)
if (utility >= beta):
return utility
if (utility > alpha):
alpha = utility
# Actions available, start from low to high index, find the best one
bestAction = transposition_table.get(stateString, None)
if (bestAction is None):
while (actions):
currentAction = actions.pop(0)
nextState = state.result(currentAction)
utilityTmp = self.minValue(nextState, alpha, beta, depth + 1)
#if (stateString == "11110111100"):
# print str(utilityTmp)
if (utilityTmp > utility):
# if (stateString == "11110111100"):
# print "WHOANELLY"
utility = utilityTmp
bestAction = currentAction
transposition_table[stateString] = (bestAction, utility,
depth)
'''
# tie break
if (utility == utilityTmp):
bestAction = transposition_table.get(stateString, None)
index = bestAction[0].index
if (currentAction.index < index):
print "tiebreaking"
bestAction = currentAction
transposition_table[stateString] = (bestAction, utility)'''
if (utility >= beta):
return utility
if (utility > alpha):
alpha = utility
return utility
else:
if (depth < bestAction[2]):
#print "REEXPLORING at " + stateString
while (actions):
currentAction = actions.pop(0)
nextState = state.result(currentAction)
utilityTmp = self.minValue(nextState, alpha, beta,
depth + 1)
if (utilityTmp > utility):
utility = utilityTmp
bestAction = currentAction
#if (nonTerminal == True):
#print "UPDATING"
#print "REUPDATING at " + stateString
transposition_table[stateString] = (bestAction,
utility, depth)
# tie break
if (utility == utilityTmp):
bestAction = transposition_table.get(stateString, None)
index = bestAction[0].index
if (currentAction.index < index):
print "tiebreaking"
bestAction = currentAction
transposition_table[stateString] = (bestAction,
utility, depth)
if (utility >= beta):
return utility
if (utility > alpha):
alpha = utility
#print "utility " + str(utility) + "bestaction 1: " + str(bestAction[1])
return utility
else:
return bestAction[1]
return bestAction[1]
def minValue(self, state, alpha, beta, depth):
global maxDepth
if (depth > maxDepth):
maxDepth = depth
global nonTerminal
stateString = ""
for i in state.board:
stateString += str(i)
stateString += str(state.player_row)
if (depth >= depth_limit):
# Terminal test
if (state.is_terminal()):
utility = state.utility(player)
print "Applying utiltiy for " + stateString + " " + str(
utility)
transposition_table[stateString] = (None, utility, depth)
return utility
else:
nonTerminal = True
value = self.evaluate(state, player.row)
print "Applying evaluation for " + stateString + " " + str(
value)
transposition_table[stateString] = (None, value, depth)
return value
bestAction = transposition_table.get(stateString, None)
#if bestAction is None:
# changed = True
# Terminal test
if (state.is_terminal()):
utility = state.utility(player)
"Applying utility not at depth limit for " + stateString + " " + str(
utility)
transposition_table[stateString] = (None, utility, depth)
return utility
# Past lowest possible utility, effectively negative infinite
utility = 2
# Get the actions from this state
actions = state.actions()
# No available actions, repeat state but switch players
if not (actions):
nextState = State(state.board, state.opponent_row, state.player)
utility = self.maxValue(nextState, alpha, beta, depth + 1)
transposition_table[stateString] = (None, utility, depth)
if (utility <= alpha):
return utility
if (beta > utility):
beta = utility
if (bestAction is None):
# Actions available
while (actions):
currentAction = actions.pop(0)
nextState = state.result(currentAction)
utilityTmp = self.maxValue(nextState, alpha, beta, depth + 1)
if (utility > utilityTmp):
utility = utilityTmp
bestAction = currentAction
transposition_table[stateString] = (bestAction, utility,
depth)
# tie break
'''
if (utility == utilityTmp):
bestAction = transposition_table.get(stateString, None)
index = bestAction[0].index
if (currentAction.index < index):
print "tiebreaking"
bestAction = currentAction
transposition_table[stateString] = (bestAction, utility)'''
if (utility <= alpha):
return utility
if (utility < beta):
beta = utility
return utility
else:
# If we're at a higher depth than the depth we last saw this state, we will explore
if (depth < bestAction[2]):
#explore
#print "REEXPLORING at " + stateString
while (actions):
currentAction = actions.pop(0)
nextState = state.result(currentAction)
utilityTmp = self.maxValue(nextState, alpha, beta,
depth + 1)
if (utility > utilityTmp):
utility = utilityTmp
bestAction = currentAction
#if (nonTerminal == True):
# print "UPDATING"
#print "Updating at " + stateString
transposition_table[stateString] = (bestAction,
utility, depth)
# tie break
if (utility == utilityTmp):
bestAction = transposition_table.get(stateString, None)
index = bestAction[0].index
if (currentAction.index < index):
print "tiebreaking"
bestAction = currentAction
transposition_table[stateString] = (bestAction,
utility, depth)
if (utility <= alpha):
return utility
if (utility < beta):
beta = utility
#print "utility " + str(utility) + "bestaction 1: " + str(bestAction[1])
return utility
else:
return bestAction[1]
return bestAction[1]