def compete(weights_1: list, weights_2: list):
"""
Plays a game between two AIs with different weights and return
the result of the game.
The second AI is in disadvantage (has a pure greedy lookahead).
Return the number of turns it took for player 1 to beat player 2,
or MAX_TURNS if player 1 didn't manage to beat player 2.
"""
print('{} versus greedy {}'.format(weights_1, weights_2))
heuristic_1 = OptimizedCombinedHeuristic(weights_1)
heuristic_2 = OptimizedCombinedHeuristic(weights_2)
game = CCGame(width=GAME_WIDTH,
player_row_span=PLAYER_ROW_SPAN,
visitors=[heuristic_1, heuristic_2])
strategy_1 = MinMaxStrategy(steps=LOOK_AHEAD,
pre_sort_moves=True,
transposition_table=True,
heuristic=heuristic_1)
strategy_2 = OnlyMaxStrategy(player=2,
steps=0,
transposition_table=True,
heuristic=heuristic_2)
turns = 0
last_boards: Set[CCGame] = set()
board_repeats = 0
while (game.state() == 0 and turns < MAX_TURNS):
strategy = (strategy_1 if game.player_turn == 1 else strategy_2)
move = strategy.select_move(game, game.player_turn)
game.apply_move_sequence(move)
if game in last_boards:
board_repeats += 1
if board_repeats == 3:
# infinite loop (tie)
print('Board repeats - tie')
return MAX_TURNS
last_boards.add(deepcopy(game))
turns += 1
state = game.state()
if state == 1:
print(f'Won in {turns} turns.')
return min(MAX_TURNS, turns)
else:
print(f'Failed to beat player 2, game state: {state}')
return MAX_TURNS
def test_player_1_wins_in_one(self):
game = CCGame(width=5, player_row_span=3)
game.board = TEST_BOARD_STRATEGY_PLAYER_1_WINS_IN_ONE
strategy = MinMaxStrategy(steps=0)
move, score = strategy._select_move(game, 1, 0, -100000, 100000)
game.apply_move_sequence(move)
self.assertEqual(100000, score)
self.assertEqual(1, game.state())
def test_player_1_wins(self):
game = CCGame(width=5, player_row_span=3)
game.board = TEST_BOARD_STRATEGY_PLAYER_1_WINS_IN_TWO
strategy = MinMaxStrategy(alpha_beta_pruning=False)
move, score = strategy._select_move(game, 1, 0, -100000, 100000)
self.assertTrue(score > 1000)
game.apply_move_sequence(move)
game.rotate_turn()
move, score = strategy._select_move(game, 1, 0, -100000, 100000)
self.assertEqual(100000, score)
game.apply_move_sequence(move)
self.assertEqual(1, game.state())
def test_player_1_wins(self):
game = CCGame(width=5, player_row_span=3)
game.board = TEST_BOARD_STRATEGY_PLAYER_1_WINS_IN_TWO
strategy = OnlyMaxStrategy(steps=1,
player=1,
heuristic=CombinedVerticalAdvance())
move, score = strategy._select_move(game, 0)
self.assertEqual(50000, score)
game.apply_move_sequence(move)
game.rotate_turn()
move, score = strategy._select_move(game, 0)
self.assertEqual(100000, score)
game.apply_move_sequence(move)
self.assertEqual(1, game.state())
def _select_move(self, game: CCGame, depth: int) -> Tuple[CCMove, float]:
"""
Returns: tuple
- position 0: best movet that can be done by the player
at this level.
- position 1: best heuristic value that can be achieved at this
level if following best move.
"""
best_move, best_score = (None, -100000.0)
if self.use_transposition_table and self.hasher:
# transposition table business logic
position_hash = self.hasher.get_hash(game)
best_move, best_score, cached_depth = self.transposition_table.get(
position_hash, (None, -100000.0, -1))
if best_move and cached_depth == depth:
return (best_move, best_score)
moves = self.available_moves(game, self.player)
if game.player_turn != self.player:
raise AssertionError("""
Player turn hasn't been rotated properly - this is likely
a software bug
""")
for move in moves:
if not best_move:
best_move = move
game.apply_move_sequence(move)
# doesn't matter what the other does
game.rotate_turn()
# check if game has already ended
if game.state() == 1:
# player 1 wins
# prefer winning in as few steps as possible
curr_score = (100000 /
(depth + 1) if self.player == 1 else -100000)
elif game.state() == 2:
# player 2 wins
# prefer winning in as few steps as possible
curr_score = (-100000 if self.player == 1 else 100000 /
(depth + 1))
else:
if depth == self.steps:
curr_score = self.heuristic.value(game, self.player)
else:
curr_score = self._select_move(game, depth + 1)[1]
# keep the best move that can be done at this level
if (curr_score > best_score):
best_score = curr_score
best_move = move
# undo movement
for _ in range(0, len(move.directions)):
game.undo_last_move()
if best_move:
if self.hasher:
# save into transposition table
self.transposition_table[position_hash] = (best_move,
best_score, depth)
return (best_move, best_score)
else:
raise AssertionError("""
No possible movements available, this must be a software bug
""")
def _select_move(self, game: CCGame, player: int, depth: int, alpha: float,
beta: float) -> Tuple[CCMove, float]:
"""
Returns: tuple
- position 0: best movem that can be done by the player
at this level.
- position 1: best heuristic value that can be achieved at this
level if following best move.
Heuristic is negative for player 2 and position for player 1.
"""
if self.hasher:
# transposition table business logic
position_hash = self.hasher.get_hash(game)
tt = (self.transposition_table_1
if player == 1 else self.transposition_table_2)
best_move, best_score, cached_depth = (tt.get(
position_hash, (None, -100000.0, -1)))
if best_move and cached_depth == depth:
return (best_move, best_score)
moves = self.available_moves(game, player)
if game.player_turn != player:
raise AssertionError("""
Player turn hasn't been rotated properly - this is likely
a software bug
""")
moves_queue = PriorityQueue() # type: ignore
for move in moves:
priority = 1
positions = move.board_positions
if self.pre_sort_moves:
advance = (positions[-1][0] - positions[0][0] if player == 1
else positions[0][0] - positions[-1][0])
if (self.extra_prunning and advance <= 0 and depth >= 3):
# prune movements down the tree which don't bring any
# extra advance
continue
# otherwise sort movements by vertical advance to maximize
# alpha-beta pruning
priority = -advance
moves_queue.put(PrioritizedCCMove(priority, move))
best_move = None
maximizing = depth % 2 == 0
best_score = -100000.0 if maximizing else 100000.0
while not moves_queue.empty():
move = moves_queue.get().move
if not best_move:
best_move = move
game.apply_move_sequence(move)
# check if game has already ended
if game.state() == 1:
# player 1 wins
# prefer winning in as few steps as possible
curr_score = (100000 / (depth + 1) if player == 1 else -100000)
if not maximizing:
curr_score = -curr_score
elif game.state() == 2:
# player 2 wins
# prefer winning in as few steps as possible
curr_score = (-100000 if player == 1 else 100000 / (depth + 1))
if not maximizing:
curr_score = -curr_score
else:
if depth == self.steps * 2: # maximizing
# approximate the score of the game by
# subtracting heuristics
curr_score = (
self.heuristic.value(game, player) -
self.heuristic.value(game, 2 if player == 1 else 1))
else:
curr_score = self._select_move(game,
2 if player == 1 else 1,
depth + 1, alpha, beta)[1]
# keep the best move that can be done at this level
if ((maximizing and curr_score > best_score)
or (not maximizing and curr_score < best_score)):
best_score = curr_score
best_move = move
# undo movement
if game.player_turn != player:
game.rotate_turn()
for _ in range(0, len(move.directions)):
game.undo_last_move()
# perform alpha-beta pruning
if self.alpha_beta_pruning:
if maximizing:
alpha = max(alpha, best_score)
else:
beta = min(beta, best_score)
if beta <= alpha:
# alpha/beta pruning
break
if best_move:
if self.hasher:
# save into transposition table
tt[position_hash] = (best_move, best_score, depth)
return (best_move, best_score)
else:
raise AssertionError("""
No possible movements available, this must be a software bug
""")
def play(board_size: int, player_row_span: int):
random.seed(1)
# (these weights were found running different experiments with the
# weight_search.py script)
oc_heuristic = OptimizedCombinedHeuristic(weights=[0.01, 0.44, 0.55])
game = CCGame(width=board_size,
player_row_span=player_row_span,
visitors=[oc_heuristic])
manual_players = set([2])
ai_players = {
1:
MinMaxStrategy(steps=1,
pre_sort_moves=True,
transposition_table=True,
heuristic=oc_heuristic)
}
start = time.time()
player_turn = 1
turns = 0
gui = PygameGUI(game)
manual_player = ManualPlayer(gui)
ai_players_perf: Dict[int, List[float]] = {1: [], 2: []}
while (game.state() == 0):
print(f'Turn: {player_turn}')
assert game.player_turn == player_turn
gui.update()
if player_turn not in manual_players:
strategy = ai_players[player_turn]
start = time.time()
move = strategy.select_move(game, player_turn)
end = time.time()
ai_players_perf[player_turn].append(end - start)
print(f'Move sequence: {move}')
print(f'Turn {turns}')
print(('Performance: '
f'{stats.describe(ai_players_perf[player_turn])}'))
print(f'Heuristic values: {oc_heuristic.value(game, 1)} - '
f'{oc_heuristic.value(game, 2)}')
game.apply_move_sequence(move)
else:
print("It's manual's player turn!")
manual_player.move(game, player_turn)
if game.player_turn == player_turn:
game.rotate_turn()
player_turn = game.player_turn
turns += 1
print('..........................')
print(f'PLAYER {game.state()} WINS after {turns} turns')
end = time.time()
print(end - start)