diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..774bf3d
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+bin
+.vscode
+a.out
diff --git a/01_simple_factory.cpp b/01_simple_factory.cpp
new file mode 100644
index 0000000..0ef5cc6
--- /dev/null
+++ b/01_simple_factory.cpp
@@ -0,0 +1,44 @@
+#include <iostream>
+#include <memory>
+
+using namespace std;
+
+class Shape {
+public:
+    virtual void draw() = 0;
+};
+
+class Circle : public Shape {
+public:
+    virtual void draw() override {
+        cout << "Circle draw" << endl;
+    }
+};
+
+class Square : public Shape {
+public:
+    virtual void draw() override {
+        cout << "Square draw" << endl;
+    }
+};
+
+class Factory {
+public:
+    unique_ptr<Shape> generate(const string& s) {
+        if (s == "circle") {
+            return make_unique<Circle>();
+        } else if (s == "square") {
+            return make_unique<Square>();
+        }
+
+        return nullptr;
+    }
+};
+
+int main() {
+    Factory f;
+    unique_ptr<Shape> s = f.generate("circle");
+    s->draw();
+    s = f.generate("square");
+    s->draw();
+}
diff --git a/notes.md b/notes.md
new file mode 100644
index 0000000..f5142e8
--- /dev/null
+++ b/notes.md
@@ -0,0 +1,5 @@
+# 设计模式笔记
+
+## 简单工厂（simple factory）
+
+简单工厂将对象的创建过程与使用过程解耦，客户端只需传入参数，而不需要关心创建的细节和具体的子类类型。这样，当需要添加新的产品子类时，只需在工厂中扩展创建逻辑，无需修改客户端代码，从而实现了对变化的封装，提升了系统的可扩展性与可维护性。