diff --git a/cpp/2302/230218-CN.cpp b/cpp/2302/230218-CN.cpp
new file mode 100644
index 0000000..38f5897
--- /dev/null
+++ b/cpp/2302/230218-CN.cpp
@@ -0,0 +1,69 @@
+#include <vector>
+#include <numeric>
+#include <algorithm>
+#include <iostream>
+
+class CustomFunction {
+public:
+	int f(int x, int y);
+};
+
+/**
+ * 1237. Find Positive Integer Solution for a Given Equation
+ * Given a callable function f(x, y) with a hidden formula and a value z, reverse engineer the formula and return all positive integer pairs x and y where f(x,y) == z. You may return the pairs in any order.
+ *
+ * While the exact formula is hidden, the function is monotonically increasing, i.e.:
+ *
+ * f(x, y) < f(x + 1, y)
+ * f(x, y) < f(x, y + 1)
+ * The function interface is defined like this:
+ *
+ * interface CustomFunction {
+ * public:
+ *   // Returns some positive integer f(x, y) for two positive integers x and y based on a formula.
+ *   int f(int x, int y);
+ * };
+ * We will judge your solution as follows:
+ *
+ * The judge has a list of 9 hidden implementations of CustomFunction, along with a way to generate an answer key of all valid pairs for a specific z.
+ * The judge will receive two inputs: a function_id (to determine which implementation to test your code with), and the target z.
+ * The judge will call your findSolution and compare your results with the answer key.
+ * If your results match the answer key, your solution will be Accepted.
+ */
+
+class Solution {
+public:
+	static std::vector<std::vector<int>> findSolution(CustomFunction& cf, int z) {
+		std::vector<int> p(1000);
+		std::iota(p.begin(), p.end(), 1);
+		auto L = std::lower_bound(p.begin(), p.end(), z, [&](int x, int y) {
+			return cf.f(x, 1000) < y;
+		}), R = std::upper_bound(p.begin(), p.end(), z, [&](int x, int y) {
+			return cf.f(y, 1) > x;
+		});
+		std::vector<std::vector<int>> ret;
+		std::for_each(L, R, [&](int x) {
+			auto L2 = std::lower_bound(p.begin(), p.end(), z, [&](int m, int n) {
+				return cf.f(x, m) < n;
+			}), R2 = std::upper_bound(p.begin(), p.end(), z, [&](int m, int n) {
+				return cf.f(x, n) > m;
+			});
+			std::for_each(L2, R2, [&](int y) {
+				ret.push_back({x, y});
+			});
+		});
+		return ret;
+	}
+};
+
+int CustomFunction::f(int x, int y) {
+	return x * y;
+}
+
+int main() {
+	CustomFunction f;
+	auto ret = Solution::findSolution(f, 5);
+	for (auto p : ret)
+		std::cout << p[0] << ", " << p[1] << std::endl;
+	return 0;
+}
diff --git a/cpp/2302/CMakeLists.txt b/cpp/2302/CMakeLists.txt
new file mode 100644
index 0000000..fcef160
--- /dev/null
+++ b/cpp/2302/CMakeLists.txt
@@ -0,0 +1,6 @@
+CMAKE_MINIMUM_REQUIRED(VERSION 3.24)
+PROJECT(2302)
+
+SET(CMAKE_CXX_STANDARD 23)
+
+ADD_EXECUTABLE(2302 230218-CN.cpp)
diff --git a/cpp/CMakeLists.txt b/cpp/CMakeLists.txt
index 2231ba5..3415eac 100644
--- a/cpp/CMakeLists.txt
+++ b/cpp/CMakeLists.txt
@@ -16,7 +16,7 @@ ENDIF()
 # Optimisation
 # SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Ofast -march=native -mtune=native -finline-functions -ffast-math -fomit-frame-pointer")
 
-ADD_EXECUTABLE(leetcode-cpp main.cpp 2302/230218.cpp)
+ADD_EXECUTABLE(leetcode-cpp main.cpp 2302/230218.cpp 2302/230218-CN.cpp)
 
 # ADD_SUBDIRECTORY(2112)
 # ADD_SUBDIRECTORY(2201)
@@ -26,5 +26,6 @@ ADD_EXECUTABLE(leetcode-cpp main.cpp 2302/230218.cpp)
 # ADD_SUBDIRECTORY(2205)
 # ADD_SUBDIRECTORY(2206)
 # ADD_SUBDIRECTORY(2207)
-ADD_SUBDIRECTORY(2210)
+# ADD_SUBDIRECTORY(2210)
+ADD_SUBDIRECTORY(2302)
 ADD_SUBDIRECTORY(more)