def move(player, board):
xlen = len(board[0])
ylen = len(board)
moves = range(xlen)
random.shuffle(moves)
best_move = -1
for m in moves:
y = r4.findMinRow(m, board)
if not r4.isValid(m, y, board):
continue
r4.setLoc(m, y, player, board)
winner = r4.findWinner(board)
r4.setLoc(m, y, 0, board)
if winner == 0:
best_move = m
elif winner == player:
best_move = m
break
return best_move
def abminimax(player, board, recur, alpha, beta):
opp = opponent(player)
winner = r4.findWinner(board)
xlen = len(board[0])
ylen = len(board)
if winner == player:
return eval_max, -1
elif winner == opp:
return eval_min, -1
if recur == 0:
return eval2(player, board), -1
best_move = -1
valid_moves = []
moves = range(xlen)
random.shuffle(moves)
for x in moves:
y = r4.findMinRow(x, board)
if r4.isValid(x, y, board):
valid_moves.append(x)
else:
continue
r4.setLoc(x, y, player, board)
score, bluh = abminimax(opp, board, recur - 1,
-beta, -alpha)
r4.setLoc(x, y, 0, board)
if score < beta:
beta = score
best_move = x
if beta <= alpha:
#print "ab pruning, returning %s" % str((beta, recur, best_move))
return -beta, best_move
# if there are no valid moves
if len(valid_moves) == 0:
beta = min(beta, 0)
# if you are going to lose...
elif beta == eval_max:
# this is a random move, because moves was shuffled
best_move = valid_moves[0]
return -beta, best_move
def minimax(player, board, recur):
opp = opponent(player)
winner = r4.findWinner(board)
xlen = len(board[0])
ylen = len(board)
if winner == player:
return eval_max, -1, 0
elif winner == opp:
return eval_min, -1, 0
if recur == 0:
return eval(player, board), -1, 0
min_score = eval_max
min_time = recur
best_move = -1
valid_moves = []
moves = range(xlen)
random.shuffle(moves)
for x in moves:
y = r4.findMinRow(x, board)
if r4.isValid(x, y, board):
valid_moves.append(x)
else:
continue
r4.setLoc(x, y, player, board)
score, m, time = minimax(opp, board, recur - 1)
r4.setLoc(x, y, 0, board)
if (score < min_score or score == min_score and time < min_time):
min_score = score
best_move = x
min_time = time
# if there are no valid moves
if len(valid_moves) == 0:
min_score = 0
# if you are going to lose...
elif min_score == eval_max:
# this is a random move, because moves was shuffled
best_move = valid_moves[0]
return -min_score, best_move, min_time + 1
def eval2(player, board):
count = 0
opp = opponent(player)
for x in range(len(board[0])):
y = r4.findMinRow(x, board)
if not r4.isValid(x, y, board):
continue
r4.setLoc(x, y, player, board)
length = r4.findLength(x, y, board)
if length >= 4:
count += 1
elif r4.isValid(x, y+1, board):
r4.setLoc(x, y+1, opp, board)
length = r4.findLength(x, y+1, board)
if length >= 4:
count -= 1
r4.setLoc(x, y+1, 0, board)
r4.setLoc(x, y, 0, board)
return count