From 82fbdec1c74699330fb3d10e7ba0e005a3def76a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jana=20D=C3=B6nszelmann?= <jana@donsz.nl>
Date: Fri, 2 Jan 2026 15:03:54 +0100
Subject: [PATCH] minor symmetry breaking: dont hash solved towers

---
 src/main.rs | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/main.rs b/src/main.rs
index 6f7dae2..48ac66b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -319,10 +319,25 @@ impl<const TOWER_HEIGHT: usize> Game<TOWER_HEIGHT> {
             }
         }
 
+        fn tower_solved<const TOWER_HEIGHT: usize>(tower: &Tower<TOWER_HEIGHT>) -> bool {
+            tower
+                .rings
+                .iter()
+                .all(|x| x.is_some() && x == &tower.rings[0])
+        }
+
         let hash_state = |s: &[Tower<TOWER_HEIGHT>]| {
             let mut hasher = DefaultHasher::default();
 
-            for x in s.iter().filter(|i| i.height() != 0).enumerate() {
+            let num_finished_towers = s.iter().filter(|i| tower_solved(*i)).count();
+
+            num_finished_towers.hash(&mut hasher);
+
+            for x in s
+                .iter()
+                .filter(|i| !tower_solved(i) && i.height() != 0)
+                .enumerate()
+            {
                 x.hash(&mut hasher);
             }