#include 
     
      using namespace std;#define DESTROY_POINTER(ptr) if (ptr) { delete ptr; ptr = NULL; }class Builder{public:    virtual ~Builder() {}    virtual void Welcome()=0;    virtual void City()=0;    virtual void End()=0;    protected:    Builder() {}};class ConcreteBuilderA : public Builder{public:    ConcreteBuilderA() {}    virtual ~ConcreteBuilderA() {}    virtual void Welcome();    virtual void City();    virtual void End();};class ConcreteBuilderB : public Builder{public:    ConcreteBuilderB() {}    virtual ~ConcreteBuilderB() {}    virtual void Welcome();    virtual void City();    virtual void End();};class Director{public:    Director(Builder* pBuilder) : m_pBuilder(pBuilder) {}    virtual ~Director() { DESTROY_POINTER(m_pBuilder); }    void Create();    private:    Builder* m_pBuilder;};void ConcreteBuilderA::Welcome(){    cout<<"welcome";}void ConcreteBuilderA::City(){    cout<<" China";}void ConcreteBuilderA::End(){    cout<<"!"<
      
       Welcome();    m_pBuilder->City();    m_pBuilder->End();}int main(int argc, char *argv[]){    Director director(new ConcreteBuilderA);    director.Create();    return 0;}