Update Best Battle Snake Logic

snakes/BestBattleSnake.py

@@ -864,6 +864,15 @@ class BestBattleSnake(TemplateSnake):
       if self._is_tail_stacked(snake["body"]):
         continue
 
+      snake_id = snake.get("id")
+      enemy_can_grow = None
+      if enemy_can_grow_cache is not None and snake_id is not None:
+        enemy_can_grow = enemy_can_grow_cache.get(snake_id)
+      if enemy_can_grow is None:
+        enemy_can_grow = self._enemy_can_grow_this_turn(snake, food_set)
+      if enemy_can_grow:
+        continue
+
       enemy_tail = snake["body"][-1]
       blocked.discard((enemy_tail["x"], enemy_tail["y"]))
 
@@ -881,6 +890,12 @@ class BestBattleSnake(TemplateSnake):
       enemy_len = enemy.get("length", len(enemy["body"]))
       enemy_tail = (enemy["body"][-1]["x"], enemy["body"][-1]["y"])
       enemy_tail_stacked = self._is_tail_stacked(enemy["body"])
+      enemy_id = enemy.get("id")
+      enemy_can_grow = None
+      if enemy_can_grow_cache is not None and enemy_id is not None:
+        enemy_can_grow = enemy_can_grow_cache.get(enemy_id)
+      if enemy_can_grow is None:
+        enemy_can_grow = self._enemy_can_grow_this_turn(enemy, food_set)
       enemy_head = enemy["head"]
       for dx, dy in self.DIRECTIONS.values():
         point = (enemy_head["x"] + dx, enemy_head["y"] + dy)
@@ -891,6 +906,7 @@ class BestBattleSnake(TemplateSnake):
           not is_constrictor
           and point == enemy_tail
           and not enemy_tail_stacked
+          and not enemy_can_grow
         )
         can_contest_my_tail = (not is_constrictor and point == my_tail and not my_tail_stacked)
 
@@ -988,7 +1004,8 @@ class BestBattleSnake(TemplateSnake):
     if self._time_exceeded(deadline) or self._remaining_ms(deadline) < self.future_planning_min_time_ms:
       return random.choice(top_moves)
 
-    candidate_moves = sorted(top_moves, key=lambda move: scores[move], reverse=True)[:3]
+    candidate_limit = max(1, self.future_planning_branch)
+    candidate_moves = sorted(top_moves, key=lambda move: scores[move], reverse=True)[:candidate_limit]
     lookahead_bonus:dict[str, float] = {}
     for move in candidate_moves:
       if self._time_exceeded(deadline):

tests/test_BestBattleSnake.py

@@ -905,7 +905,7 @@ class TestBestBattleSnake(unittest.TestCase):
       enemy_can_grow_cache={"enemy": True},
     )
 
-    self.assertNotIn((0, 1), blocked)
+    self.assertIn((0, 1), blocked)
 
   def test_enemy_attack_map_allows_enemy_tail_move_when_enemy_can_grow(self):
     snake = BestBattleSnake()
@@ -948,7 +948,7 @@ class TestBestBattleSnake(unittest.TestCase):
       enemy_can_grow_cache={"enemy": True},
     )
 
-    self.assertEqual(attack_map.get((2, 3)), 4)
+    self.assertIsNone(attack_map.get((2, 3)))
 
   def test_future_planning_prefers_non_trap_path(self):
     snake = BestBattleSnake()