diff --git a/cpp/2203/220309-CN.cpp b/cpp/2203/220309-CN.cpp
new file mode 100644
index 0000000..94c5839
--- /dev/null
+++ b/cpp/2203/220309-CN.cpp
@@ -0,0 +1,39 @@
+#include <vector>
+#include <cstring>
+#include <iostream>
+
+class Solution {
+public:
+	static int bestRotation(const std::vector<int>& nums) {
+		int n = nums.size(), rotates[n];
+		std::memset(rotates, 0, sizeof rotates);
+
+		for (int i = 0; i < n; ++i)
+			if (nums[i] < n)
+				++rotates[(i - nums[i] + 1 + n) % n];
+
+		int ret = 0, retMax = 0;
+		for (int i = 0; i < n; ++i)
+			if (nums[i] <= i)
+				++retMax;
+
+		int now = retMax;
+		for (int i = 1; i <= n; ++i) {
+			// i -> i + 1
+			now -= rotates[i % n];
+			if (nums[i - 1] < n)
+				++now;
+			if (now > retMax) {
+				retMax = now;
+				ret = i;
+			}
+		}
+		return ret % n;
+	}
+};
+
+int main() {
+	std::cout << Solution::bestRotation({2,3,1,4,0}) << "\n";
+	std::cout << Solution::bestRotation({1,3,0,2,4});
+	return 0;
+}
diff --git a/cpp/2203/CMakeLists.txt b/cpp/2203/CMakeLists.txt
index 1b94df8..35f8a5f 100644
--- a/cpp/2203/CMakeLists.txt
+++ b/cpp/2203/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2203)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2203 220308-CN.cpp)
+ADD_EXECUTABLE(2203 220309-CN.cpp)