From f3d0297da50782a5398e23deb1871a3d15fd44ca Mon Sep 17 00:00:00 2001
From: Bert Peters <bert@bertptrs.nl>
Date: Wed, 5 Dec 2018 22:37:22 +0100
Subject: [PATCH] Bithack optimizations, why not.

It saves a branch and a (possibly inlined) function call, but it also
halves the runtime.
---
 2018/src/day05.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/2018/src/day05.rs b/2018/src/day05.rs
index a573ee1..a5e506f 100644
--- a/2018/src/day05.rs
+++ b/2018/src/day05.rs
@@ -13,7 +13,7 @@ impl Day05 {
     fn reduce(mut data: Vec<u8>) -> usize {
         let mut dptr = 0;
         for iptr in 0..data.len() {
-            if dptr > 0 && (data[iptr].eq_ignore_ascii_case(&data[dptr - 1])) && data[iptr] != data[dptr - 1] {
+            if dptr > 0 && (data[iptr] ^ data[dptr - 1]) == 32 {
                 dptr -= 1;
             } else {
                 data[dptr] = data[iptr];