Interpret 模式

#include <cstdlib>
#include <iostream>
#include <string>
using namespace std;
class Context
{
public:
  Context(){}
  virtual ~Context(){}
  virtual void Print(){cout<<"I am Context！";}
};
class Expression
{
public:
  Expression(){}
  virtual ~Expression(){}
  virtual void Interpret(Context* p) = 0;
};
class TeminalExpression:public Expression
{
  string m_Data;
public:
  TeminalExpression(string str):m_Data(str){}
  virtual ~TeminalExpression(){}
  virtual void Interpret(Context* p){
    p->Print();
    cout<<"结束表达式:"<<m_Data<<endl;
  }
};
class UnteminalExpression:public Expression
{
  Expression* m_pEx;
  int nTime;
public:
  UnteminalExpression(Expression* p,int n):m_pEx(p),nTime(n){}
  virtual ~UnteminalExpression(){}
  virtual void Interpret(Context* p){
    for(int i = 0; i < nTime; i++){
      cout<<i<<":";
      m_pEx->Interpret(p);
    }
  }
};
int main(int argc, char *argv[])
{
    Context* c = new Context;
    TeminalExpression* pTem = new TeminalExpression("hello");
    UnteminalExpression* pUntem = new UnteminalExpression(pTem,2);
    pUntem->Interpret(c);
    delete pUntem;
    delete pTem;
    delete c;
    system("PAUSE");
    return EXIT_SUCCESS;
}