diff --git a/cpp/2204/220416.cpp b/cpp/2204/220416.cpp
new file mode 100644
index 0000000..b90a5df
--- /dev/null
+++ b/cpp/2204/220416.cpp
@@ -0,0 +1,26 @@
+#include <functional>
+
+struct TreeNode {
+	int val;
+	TreeNode* left;
+	TreeNode* right;
+	explicit TreeNode(int x, TreeNode* left = nullptr, TreeNode* right = nullptr) : val(x), left(left), right(right) {}
+};
+
+class Solution {
+public:
+	static TreeNode* convertBST(TreeNode* root) {
+		if (!root)
+			return nullptr;
+		int x = 0;
+		std::function<void(TreeNode*)> reversedInOrderTraverse = [&](TreeNode* r) {
+			if (r->right)
+				reversedInOrderTraverse(r->right);
+			r->val = (x += r->val);
+			if (r->left)
+				reversedInOrderTraverse(r->left);
+		};
+		reversedInOrderTraverse(root);
+		return root;
+	}
+};
diff --git a/cpp/2204/CMakeLists.txt b/cpp/2204/CMakeLists.txt
index b3f2d3c..39ae9f1 100644
--- a/cpp/2204/CMakeLists.txt
+++ b/cpp/2204/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2204)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2204 220413-CN.cpp)
+ADD_EXECUTABLE(2204 220416.cpp)