def rollout(self):
'''
Monte Carlo simulation: simulate a randomized game from the current node until it reaches an end of the game.
Outputs:
e: the result of the game (X player won:1, tie:0, lose: -1), an integer scalar.
Hint: you could use PlayerRandom in problem 1.
'''
#########################################
## INSERT YOUR CODE HERE
P1 = PlayerRandom()
P2 = PlayerRandom()
s = np.copy(self.s)
e = TicTacToe.check(s)
if (self.x == 1):
while (e == None and len(np.where(s == 0)) > 0):
r, c = P1.play(s, 1)
s[r][c] = 1
e = TicTacToe.check(s)
if (e == None and len(np.where(s == 0)) > 0):
r, c = P2.play(s, -1)
s[r][c] = -1
e = TicTacToe.check(s)
else:
while (e == None and len(np.where(s == 0)) > 0):
r, c = P1.play(s, -1)
s[r][c] = -1
e = TicTacToe.check(s)
if (e == None and len(np.where(s == 0)) > 0):
r, c = P2.play(s, 1)
s[r][c] = 1
e = TicTacToe.check(s)
#########################################
return e
def rollout(self):
'''
Monte Carlo simulation: simulate a randomized game from the current node until it reaches an end of the game.
Outputs:
e: the result of the game (X player won:1, tie:0, lose: -1), an integer scalar.
Hint: you could use PlayerRandom in problem 1.
'''
s = np.copy(self.s)
x = self.x
while TicTacToe.check(s) is None:
player_random = PlayerRandom()
r, c = player_random.play(s, x=x)
s[r, c] = x
x = -x
e = TicTacToe.check(s)
return e
def expand(self):
'''
Expand the current tree node for one-level.
Add one child node for each possible next move in the game.
Inputs:
node: the current tree node to be expanded
'''
# if the game has already ended, return/exit without expanding the tree
if TicTacToe.check(self.s) is not None:
return
# if the game has not ended yet, expand the current node with one child node for each valid move
all_moves = TicTacToe.avail_moves(self.s)
for r, c in all_moves:
# update s
s = np.copy(self.s)
s[r, c] = 1 if self.x == 1 else -1
node = Node(s, x=-self.x, parent=self)
self.c.append(node)
def expand(self):
'''
Expand the current tree node for one-level.
Add one child node for each possible next move in the game.
Inputs:
node: the current tree node to be expanded
'''
#########################################
## INSERT YOUR CODE HERE
# if the game has already ended, return/exit without expanding the tree
if (TicTacToe.check(self.s) != None):
return
# if the game has not ended yet, expand the current node with one child node for each valid move
valid_moves = TicTacToe.avail_moves(self.s)
for move in valid_moves:
new_s = np.copy(self.s)
i = move[0]
j = move[1]
new_s[i][j] = self.x
Child = Node(s=new_s, x=self.x * -1, parent=self)
self.c.append(Child)