class Singleton {public:  static Singleton& getInstance() {    static Singleton instance;    return instance;  }
  void show(){    std::cout << "Singleton\n";  }
private:  Singleton() = default;  ~Singleton() = default;  Singleton(const Singleton& instance) = delete;  Singleton& operator=(const Singleton& instance) = delete;};

#include <iostream>#include <vector>
class Component {public:  Component(const std::string& name): _name(name){};  virtual void draw() = 0;  virtual ~Component() = default;
protected:  std::string _name;};
class Container : public Component {public:  Container(const std::string& name): Component(name){};  void addComponent(Component& com) {_comList.push_back(&com);};  virtual void draw();  ~Container() = default;private:  std::vector<Component*> _comList;};
void Container::draw() {  for (auto& item : _comList) {    item->draw();  }}
class WinForm : public Container{public:  WinForm(const std::string name): Container(name){};  virtual void draw();  ~WinForm() = default;};
void WinForm::draw() {  std::cout << "WinForm (" << _name << ")\n";  Container::draw();}
class Frame : public Container{public:  Frame(const std::string name): Container(name){};  virtual void draw();  ~Frame() = default;};
void Frame::draw() {  std::cout << "Frame (" << _name << ")\n";  Container::draw();}
class Picture : public Component {public:  Picture(const std::string& name) : Component(name){};  virtual void draw() {std::cout << "Picture (" << _name << ")\n";};  ~Picture() = default;};
class Button : public Component {public:  Button(const std::string& name) : Component(name){};  virtual void draw() {std::cout << "Button (" << _name << ")\n";};  ~Button() = default;};
class Label : public Component {public:  Label(const std::string& name) : Component(name){};  virtual void draw() {std::cout << "Label (" << _name << ")\n";};  ~Label() = default;};
class LinkLabel : public Component {public:  LinkLabel(const std::string& name) : Component(name){};  virtual void draw() {std::cout << "LinkLabel (" << _name << ")\n";};  ~LinkLabel() = default;};
class TextBox : public Component {public:  TextBox(const std::string& name) : Component(name){};  virtual void draw() {std::cout << "TextBox (" << _name << ")\n";};  ~TextBox() = default;};
class PasswordBox : public Component {public:  PasswordBox(const std::string& name) : Component(name){};  virtual void draw() {std::cout << "PasswordBox (" << _name << ")\n";};  ~PasswordBox() = default;};
class CheckBox : public Component {public:  CheckBox(const std::string& name) : Component(name){};  virtual void draw() {std::cout << "CheckBox (" << _name << ")\n";};  ~CheckBox() = default;};

int main(){
    WinForm win = WinForm("Window窗口");    Picture pic = Picture("Logo圖片");    Button btn1 = Button("登錄");    Button btn2 = Button("註冊");    Frame frame = Frame("Frame1");    Label label1 = Label("用戶名");    TextBox textB1 = TextBox("文本框");    Label label2 = Label("密碼");    PasswordBox passB = PasswordBox("密碼框");    CheckBox checkB = CheckBox("複選框");    Label label3 = Label("記住用戶名");    LinkLabel link = LinkLabel("忘記密碼");
    win.addComponent(pic);    win.addComponent(btn1);    win.addComponent(btn2);    win.addComponent(frame);    frame.addComponent(label1);    frame.addComponent(textB1);    frame.addComponent(label2);    frame.addComponent(passB);    frame.addComponent(checkB);    frame.addComponent(label3);    frame.addComponent(link);
    win.draw();}