diff --git a/cpp/2304/230420-CN.cpp b/cpp/2304/230420-CN.cpp
new file mode 100644
index 0000000..6df1b3c
--- /dev/null
+++ b/cpp/2304/230420-CN.cpp
@@ -0,0 +1,41 @@
+#include <algorithm>
+#include <functional>
+#include <unordered_map>
+#include <vector>
+#include <iostream>
+
+/**
+ * 1187. Make Array Strictly Increasing
+ *
+ * Given two integer arrays arr1 and arr2, return the minimum number of operations (possibly zero) needed to make arr1 strictly increasing.
+ * In one operation, you can choose two indices 0 <= i < arr1.length and 0 <= j < arr2.length and do the assignment arr1[i] = arr2[j].
+ * If there is no way to make arr1 strictly increasing, return -1.
+ */
+
+class Solution {
+public:
+	static int makeArrayIncreasing(const std::vector<int>&, std::vector<int>);
+};
+
+int Solution::makeArrayIncreasing(const std::vector<int>& p, std::vector<int> q) {
+	std::sort(q.begin(), q.end());
+	std::unordered_map<int, int> ans[2048];
+	std::function<int(int, int)> dp = [&](int pos, int prev) {
+		if (pos >= p.size())
+			return 0;
+		if (ans[pos].count(prev))
+			return ans[pos][prev];
+		int ret = 0x7FFFFFFE;
+		if (auto it = std::upper_bound(q.begin(), q.end(), prev); it != q.end())
+			ret = std::min(ret, dp(pos + 1, *it) + 1);
+		if (p[pos] > prev)
+			ret = std::min(ret, dp(pos + 1, p[pos]));
+		return ans[pos][prev] = ret;
+	};
+	return dp(0, -1) > 99999 ? -1 : dp(0, -1);
+}
+
+int main() {
+	std::cout << Solution::makeArrayIncreasing({1,5,3,6,7},{6,3,3,1});
+	return 0;
+}
diff --git a/cpp/2304/CMakeLists.txt b/cpp/2304/CMakeLists.txt
index 04b7d85..977590a 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 230419-CN.cpp)
+ADD_EXECUTABLE(2304 230420-CN.cpp)