From 09b590e9276cb9bdb17d47ad73d1df24fa0093dc Mon Sep 17 00:00:00 2001
From: Bert Peters <bert@bertptrs.nl>
Date: Wed, 29 Dec 2021 15:36:46 +0100
Subject: [PATCH] Update southbound comment

---
 2021/src/day25.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/2021/src/day25.rs b/2021/src/day25.rs
index 605ef6d..d4ac91e 100644
--- a/2021/src/day25.rs
+++ b/2021/src/day25.rs
@@ -35,7 +35,7 @@ fn advance(width: usize, state: &mut [u8]) -> bool {
         }
     }
 
-    // Now the southbound herd. Y in the outer loop for better cache locality
+    // Then move the southbound herd. Need to do by column because of the first entry special case
     for x in 0..width {
         let last_index = state.len() - width + x;
         let swap_last = state[x] == b'.' && state[last_index] == b'v';