From e159e90cf9215ad4f7a65f95193c523b2fa907ee Mon Sep 17 00:00:00 2001
From: Vincent Zalzal <vincent.zalzal@gmail.com>
Date: Sat, 23 May 2020 18:19:36 -0400
Subject: [PATCH 1/2] Add computus in C++

---
 contents/computus/code/c++/gauss_easter.cpp | 57 +++++++++++++++++++++
 contents/computus/computus.md               |  2 +
 2 files changed, 59 insertions(+)
 create mode 100644 contents/computus/code/c++/gauss_easter.cpp

diff --git a/contents/computus/code/c++/gauss_easter.cpp b/contents/computus/code/c++/gauss_easter.cpp
new file mode 100644
index 000000000..fbb7c0873
--- /dev/null
+++ b/contents/computus/code/c++/gauss_easter.cpp
@@ -0,0 +1,57 @@
+#include <iostream>
+#include <string>
+
+std::string computus(int year, bool servois = false) {
+  // Year's position on the 19 year metonic cycle
+  int a = year % 19;
+
+  // Century index
+  int k = year / 100;
+
+  // Shift of metonic cycle, add a day offset every 300 years
+  int p = (13 + 8 * k) / 25;
+
+  // Correction for non-observed leap days
+  int q = k / 4;
+
+  // Correction to starting point of calculation each century
+  int M = (15 - p + k - q) % 30;
+
+  // Number of days from March 21st until the full moon
+  int d = (19 * a + M) % 30;
+
+  // Returning if user wants value for Servois' table
+  if (servois)
+    return std::to_string((21 + d) % 31);
+
+  // Finding the next Sunday
+  // Century-based offset in weekly calculation
+  int N = (4 + k - q) % 7;
+
+  // Correction for leap days
+  int b = year % 4;
+  int c = year % 7;
+
+  // Days from d to next Sunday
+  int e = (2 * b + 4 * c + 6 * d + N) % 7;
+
+  // Historical corrections for April 26 and 25
+  if ((d == 29 && e == 6) || (d == 28 && e == 6 && a > 10))
+    e = -1;
+
+  // Determination of the correct month for Easter
+  return 22 + d + e > 31 ? "April " + std::to_string(d + e - 9)
+                         : "March " + std::to_string(22 + d + e);
+}
+
+// Here, we will output the date of the Paschal full moon (using Servois
+// notation), and Easter for 2020-2030
+int main() {
+  std::cout << "The following are the dates of the Paschal full moon (using "
+               "Servois notation) and the date of Easter for 2020-2030 AD:\n"
+               "Year\tServois number\tEaster\n";
+
+  for (int year = 2020; year <= 2030; year++)
+    std::cout << year << "\t\t" << computus(year, true) << '\t'
+              << computus(year) << std::endl;
+}
diff --git a/contents/computus/computus.md b/contents/computus/computus.md
index 3b5459e7f..e8e54ba8c 100644
--- a/contents/computus/computus.md
+++ b/contents/computus/computus.md
@@ -287,6 +287,8 @@ For now, we have the code outputting a tuple of $$d$$ and $$e$$, so users can us
 [import, lang:"crystal"](code/crystal/gauss_easter.cr)
 {% sample lang="c" %}
 [import, lang:"c"](code/c/gauss_easter.c)
+{% sample lang="cpp" %}
+[import, lang:"cpp"](code/c++/gauss_easter.cpp)
 {% endmethod %}
 
 

From d58a65e1b7e4673b07c6c7f8521799057d9200ff Mon Sep 17 00:00:00 2001
From: Vincent Zalzal <vincent.zalzal@gmail.com>
Date: Sun, 24 May 2020 12:39:04 -0400
Subject: [PATCH 2/2] Add braces

---
 contents/computus/code/c++/gauss_easter.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/contents/computus/code/c++/gauss_easter.cpp b/contents/computus/code/c++/gauss_easter.cpp
index fbb7c0873..0f0c1cf78 100644
--- a/contents/computus/code/c++/gauss_easter.cpp
+++ b/contents/computus/code/c++/gauss_easter.cpp
@@ -21,8 +21,9 @@ std::string computus(int year, bool servois = false) {
   int d = (19 * a + M) % 30;
 
   // Returning if user wants value for Servois' table
-  if (servois)
+  if (servois) {
     return std::to_string((21 + d) % 31);
+  }
 
   // Finding the next Sunday
   // Century-based offset in weekly calculation
@@ -36,8 +37,9 @@ std::string computus(int year, bool servois = false) {
   int e = (2 * b + 4 * c + 6 * d + N) % 7;
 
   // Historical corrections for April 26 and 25
-  if ((d == 29 && e == 6) || (d == 28 && e == 6 && a > 10))
+  if ((d == 29 && e == 6) || (d == 28 && e == 6 && a > 10)) {
     e = -1;
+  }
 
   // Determination of the correct month for Easter
   return 22 + d + e > 31 ? "April " + std::to_string(d + e - 9)
@@ -51,7 +53,8 @@ int main() {
                "Servois notation) and the date of Easter for 2020-2030 AD:\n"
                "Year\tServois number\tEaster\n";
 
-  for (int year = 2020; year <= 2030; year++)
+  for (int year = 2020; year <= 2030; year++) {
     std::cout << year << "\t\t" << computus(year, true) << '\t'
               << computus(year) << std::endl;
+  }
 }