add constrictor mode

battlesnake/src/logic.rs

@@ -109,6 +109,7 @@ pub fn get_move(game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Opt
         turn,
         game.ruleset.settings.food_spawn_chance,
         game.ruleset.settings.minimum_food,
+        game.ruleset.name == "constrictor",
     );
     let possible_actions = board.possible_actions().get(&game_info.my_token).cloned()?;
     if possible_actions.len() == 1 {

battlesnake/src/simulation.rs

@@ -46,6 +46,9 @@ pub struct Board {
     min_food: u8,
     /// Alive snakes
     snakes: BTreeMap<SnakeToken, Battlesnake>,
+    /// True when playing constrictor mode. In this mode the snakes don't loose health and grow
+    /// every turn
+    constrictor: bool,
 }
 
 impl Board {
@@ -55,6 +58,7 @@ impl Board {
         turn: i32,
         food_chance: u8,
         min_food: u8,
+        constrictor: bool,
     ) -> Self {
         let width = board.width;
         debug_assert!(width > 0);
@@ -78,6 +82,7 @@ impl Board {
             food_chance,
             min_food,
             snakes,
+            constrictor,
         }
     }
 
@@ -107,7 +112,7 @@ impl Board {
         // feed snakes
         for snake in &mut self.snakes.values_mut() {
             let head = snake.head();
-            if self.food.remove(head) {
+            if self.constrictor || self.food.remove(head) {
                 snake.health = MAX_HEALTH;
             }
         }