组合模式（C++）

#include <iostream>
#include <string>
#include <vector>
using namespace std;

class Composite
{
public:
    Composite():_name(""){}
    Composite(string name):_name(name){}
    virtual ~Composite(){}

    virtual void operation()=0;    
    virtual void add(Composite*){}
    virtual void del(Composite*){}
    virtual Composite* find(int index){return NULL;}

protected:
    string _name;
};

class Leaf : public Composite
{
public:
    Leaf(){}
    Leaf(string name){_name=name;}
    virtual ~Leaf(){}
    void operation(){cout<<_name<<endl;}
};

class subComposite : public Composite
{
public:
    subComposite():level(0){}
    subComposite(string name):level(0){_name=name;}
    virtual ~subComposite(){}

    void add(Composite*);
    void del(Composite*);
    Composite* find(int index);
    void operation();

private:
    vector<Composite*> v_pcom;
    int level;
};

void subComposite::add(Composite* com)
{
    level++;
    v_pcom.push_back(com);
}

void subComposite::del(Composite* com)
{
    v_pcom.pop_back();
}

Composite* subComposite::find(int index)
{
    return v_pcom[index];
}

void subComposite::operation()
{
    for(int i=0;i<level;i++)
        cout<<"+";
    cout<<_name<<endl;
    vector<Composite*>::iterator it;
    for (it=v_pcom.begin();it!=v_pcom.end();it++)
    {
        (*it)->operation();
    }
}

int main()
{
    Composite* psubcom=new subComposite("动物");
    Composite* psubcom1=new subComposite("非哺乳动物");
    Composite* pleaf1=new Leaf("鸟");
    Composite* pleaf2=new Leaf("鱼");
    Composite* psubcom2=new subComposite("哺乳动物");
    Composite* pleaf3=new Leaf("人");    
    psubcom1->add(pleaf1);
    psubcom1->add(pleaf2);
    psubcom2->add(pleaf3);
    psubcom->add(psubcom1);
    psubcom->add(psubcom2);
    psubcom->operation();

    delete pleaf1;
    delete pleaf2;
    delete pleaf3;
    delete psubcom1;
    delete psubcom2;
    delete psubcom;

    system("pause");
    return 0;
}