From 6cb0fe155082a55c71b4f1203096223cce38ee31 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20K=C3=A4nner?= <max.kaenner@gmail.com>
Date: Sun, 6 Oct 2024 21:55:15 +0200
Subject: [PATCH] evaluate stop condition at every simulation step

---
 battlesnake/src/logic.rs | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/battlesnake/src/logic.rs b/battlesnake/src/logic.rs
index f2caf36..324f79c 100644
--- a/battlesnake/src/logic.rs
+++ b/battlesnake/src/logic.rs
@@ -217,11 +217,16 @@ impl Node {
         board: &mut simulation::Board,
         deadline: &Instant,
     ) -> Result<Option<SnakeToken>, DeadlineError> {
-        let winner = if self.statistic.played == 0 {
+        let stop_condition =
+            |board: &simulation::Board| board.alive_snakes() <= 1 || Instant::now() >= *deadline;
+        let winner = if stop_condition(board) {
+            if Instant::now() >= *deadline {
+                return Err(DeadlineError);
+            }
+            board.snakes().next()
+        } else if self.statistic.played == 0 {
             // We didn't simulate a game for this node yet. Do that
-            board.simulate_until(&mut thread_rng(), |board| {
-                board.alive_snakes() <= 1 || Instant::now() >= *deadline
-            });
+            board.simulate_until(&mut thread_rng(), stop_condition);
             if Instant::now() >= *deadline {
                 return Err(DeadlineError);
             }
@@ -252,9 +257,6 @@ impl Node {
                 })
                 .collect();
 
-            if Instant::now() >= *deadline {
-                return Err(DeadlineError);
-            }
             board.simulate_actions(&actions, &mut thread_rng());
             let winner = self
                 .childs