C++设计模式学习之策略模式

#include<stdlib.h>
#include<iostream>
using namespace std;
class Strategy{
public:
virtual void SymEncrypt() = 0;
};

class Des :public Strategy{
public:
virtual void SymEncrypt(){
cout << "使用DES加密" << endl;
}
};

class AES :public Strategy{
public:
virtual void SymEncrypt(){
cout << "AES加密" << endl;
}
};

class Context{
public:
Context(Strategy *s){
p = s;
}
void Operate(){
p->SymEncrypt();
}
protected:
private:
Strategy *p;
};
void main(){
//Strategy *s = NULL;
//s = new AES;
//s->SymEncrypt();
//delete s;

Strategy *s = NULL;
Context *ctx = NULL;
s = new AES;
ctx = new Context(s);
ctx->Operate();
delete s;
delete ctx;
system("pause");
}