From ce8a6a1c795aec1b8483dcc6c1c13f094cd9e41c Mon Sep 17 00:00:00 2001
From: Eric Mertens <emertens@galois.com>
Date: Fri, 11 Nov 2022 15:10:56 -0800
Subject: [PATCH] Update 24.cpp

---
 2019/24.cpp | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/2019/24.cpp b/2019/24.cpp
index f6eddf5..aac02d9 100644
--- a/2019/24.cpp
+++ b/2019/24.cpp
@@ -112,7 +112,7 @@ auto Neighbor2(std::pair<Coord, std::int64_t> cd) {
 }
 
 template<class F, class C>
-auto Step(std::set<C> const& bugs, F const& neighbors)
+auto Step(std::set<C> const& bugs, F neighbors)
 {
   std::map<C, int> adjacent;
   for (auto const& x : bugs) {
@@ -132,7 +132,7 @@ auto Step(std::set<C> const& bugs, F const& neighbors)
   return result;
 }
 
-auto Bio(std::set<Coord> const& bugs) {
+auto Bio(std::set<Coord> const& bugs) -> std::uint32_t {
   std::uint32_t result = 0;
   for (auto const& c : bugs) {
     result |= 1U << (5 * c.y + c.x);
@@ -140,15 +140,14 @@ auto Bio(std::set<Coord> const& bugs) {
   return result;
 }
 
-auto Part1(std::set<Coord> const& bugs) {
-  std::int64_t n = 0;
+auto Part1(std::set<Coord> const& bugs) -> std::uint32_t {
   auto cursor = bugs;
   std::set<std::uint32_t> seen;
-  while (seen.insert(Bio(cursor)).second) {
-    n++;
+  std::uint32_t bio;
+  while (seen.insert(bio = Bio(cursor)).second) {
     cursor = Step(cursor, Neighbor1);
   }
-  return Bio(cursor);
+  return bio;
 }
 
 auto Part2(std::set<Coord> const& bugs) {