From 0d3c9e3422a0a154ec99f0c3f8e35fca82768ed0 Mon Sep 17 00:00:00 2001
From: Eric Mertens <emertens@galois.com>
Date: Fri, 13 Jan 2023 17:03:44 -0800
Subject: [PATCH] fix divmod

---
 2022/25.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/2022/25.cpp b/2022/25.cpp
index 633b450..013117e 100644
--- a/2022/25.cpp
+++ b/2022/25.cpp
@@ -19,7 +19,7 @@ auto DivMod(T dividend, T divisor) -> std::pair<T, T>
 {
   auto const quotient  = dividend / divisor;
   auto const remainder = dividend % divisor;
-  if ((remainder >= 0) == (divisor >= 0)) {
+  if (remainder == 0 || (remainder > 0) == (divisor > 0)) {
     return {quotient, remainder};
   } else {
     return {quotient - 1, remainder + divisor};
@@ -101,6 +101,11 @@ TEST_SUITE("2022-25 examples") {
     CHECK(DivMod<int>(-2,5) == std::make_pair(-1,3));
     CHECK(DivMod<int>(2,-5) == std::make_pair(-1,-3));
     CHECK(DivMod<int>(-2,-5) == std::make_pair(0,-2));
+    
+    CHECK(DivMod<int>(-5,-5) == std::make_pair(1,0));
+    CHECK(DivMod<int>(-5,5) == std::make_pair(-1,0));
+    CHECK(DivMod<int>(5,-5) == std::make_pair(-1,0));
+    CHECK(DivMod<int>(-5,-5) == std::make_pair(1,0));
   }
 }