From 5d896a3452bb1b5d5b9ec6b12adc2958fe70aabd Mon Sep 17 00:00:00 2001
From: Eatswap <root@eatswap.org>
Date: Wed, 5 Apr 2023 14:50:26 +0800
Subject: [PATCH] add: 230405-CN

---
 cpp/2304/230405-CN.cpp  | 25 +++++++++++++++++++++++++
 cpp/2304/CMakeLists.txt |  2 +-
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 cpp/2304/230405-CN.cpp

diff --git a/cpp/2304/230405-CN.cpp b/cpp/2304/230405-CN.cpp
new file mode 100644
index 0000000..476701c
--- /dev/null
+++ b/cpp/2304/230405-CN.cpp
@@ -0,0 +1,25 @@
+#include <iostream>
+#include <numeric>
+
+/**
+ * 2427. Number of Common Factors
+ *
+ * Given two positive integers a and b, return the number of common factors of a and b.
+ * An integer x is a common factor of a and b if x divides both a and b.
+ */
+
+class Solution {
+public:
+	static constexpr inline int commonFactors(int a, int b) {
+		int x = std::gcd(a, b), ret = 0;
+		for (int i = 1; i * i <= x; ++i)
+			ret += ((x % i == 0) << 1) - (i * i == x);
+		return ret;
+	}
+};
+
+int main() {
+	std::cout << Solution::commonFactors(452, 392);
+	std::cout << std::gcd(452, 392);
+	return 0;
+}
diff --git a/cpp/2304/CMakeLists.txt b/cpp/2304/CMakeLists.txt
index e14ecf6..dbe10aa 100644
--- a/cpp/2304/CMakeLists.txt
+++ b/cpp/2304/CMakeLists.txt
@@ -4,4 +4,4 @@ PROJECT(2304)
 SET(CMAKE_CXX_STANDARD 23)
 SET(CMAKE_EXPORT_COMPILE_COMMANDS true)
 
-ADD_EXECUTABLE(2304 230404.cpp)
+ADD_EXECUTABLE(2304 230405-CN.cpp)