【c++设计模式】组合模式

结构型模式

8）组合模式

当需要以树形结构来表示部分 - 整体的层次结构时使用。
组合模式中只有一种角色，就是要表示的对象。

//对象基类
class Department{
public:
    Department(string strName): m_strName(strName){}
    void addSubDepartment(Department* p){
        m_vecDep.push_back(p);
    }
    virtual ~Department(){
        list<Department*>::iterator it;
        for(it = m_vecDep.begin();it!=m_vecDep.end();it++){
            if(*it!=NULL){
                delete (*it);
                (*it) = NULL;
            }
        }
    }
private:
    string m_strName;
    list<Department* > m_vecDep; //这里为核心，就是包含了指向同样类型指针的容器
};


class Level1Depart : public Department{
public:
    Level1Depart(string name) : Department(name){}
};

class Level2Depart : public Department{
public:
    Level2Depart(string name):Department(name){}
};

int main()
{
    //一级部门
    Department* a0 = new Department("A1");
    
    //二级部门
    Department* b1 = new Level1Depart("B1");
    Department* b2 = new Level1Depart("B2");
    
    //三级部门
    Department* c1 = new Level2Depart("C1");
    Department* c2 = new Level2Depart("C2");
    Department* c3 = new Level2Depart("C3");
    Department* c4 = new Level2Depart("C4");
    
    a0->addSubDepartment(b1);
    a0->addSubDepartment(b2);
    
    b1->addSubDepartment(c1);
    b1->addSubDepartment(c2);
    
    b2->addSubDepartment(c3);
    b2->addSubDepartment(c4);
    
}