设计模式-1.8组合模式
组合模式：将对象组合成树形结构以表示“部分-整体”的层次结构。组合使得用户对单个对象和组合对象的使用具有一致性。
1 class Company 2 { 3 public: 4 Company(string name) { m_name = name; } 5 virtual ~Company(){} 6 virtual void Add(Company *pCom){} 7 virtual void Show(int depth) {} 8 protected: 9 string m_name; 10 }; 11 //具体公司 12 class ConcreteCompany : public Company 13 { 14 public: 15 ConcreteCompany(string name): Company(name) {} 16 virtual ~ConcreteCompany() {} 17 void Add(Company *pCom) { m_listCompany.push_back(pCom); } //位于树的中间，可以增加子树 18 void Show(int depth) 19 { 20 for(int i = 0;i < depth; i++) 21 cout<<"-"; 22 cout<<m_name<<endl; 23 list<Company *>::iterator iter=m_listCompany.begin(); 24 for(; iter != m_listCompany.end(); iter++) //显示下层结点 25 (*iter)->Show(depth + 2); 26 } 27 private: 28 list<Company *> m_listCompany; 29 }; 30 //具体的部门，财务部 31 class FinanceDepartment : public Company 32 { 33 public: 34 FinanceDepartment(string name):Company(name){} 35 virtual ~FinanceDepartment() {} 36 virtual void Show(int depth) //只需显示，无限添加函数，因为已是叶结点 37 { 38 for(int i = 0; i < depth; i++) 39 cout<<"-"; 40 cout<<m_name<<endl; 41 } 42 }; 43 //具体的部门，人力资源部 44 class HRDepartment :public Company 45 { 46 public: 47 HRDepartment(string name):Company(name){} 48 virtual ~HRDepartment() {} 49 virtual void Show(int depth) //只需显示，无限添加函数，因为已是叶结点 50 { 51 for(int i = 0; i < depth; i++) 52 cout<<"-"; 53 cout<<m_name<<endl; 54 } 55 };
1 int main() 2 { 3 Company *root = new ConcreteCompany("总公司"); 4 Company *leaf1=new FinanceDepartment("财务部"); 5 Company *leaf2=new HRDepartment("人力资源部"); 6 root->Add(leaf1); 7 root->Add(leaf2); 8 9 //分公司A 10 Company *mid1 = new ConcreteCompany("分公司A"); 11 Company *leaf3=new FinanceDepartment("财务部"); 12 Company *leaf4=new HRDepartment("人力资源部"); 13 mid1->Add(leaf3); 14 mid1->Add(leaf4); 15 root->Add(mid1); 16 //分公司B 17 Company *mid2=new ConcreteCompany("分公司B"); 18 FinanceDepartment *leaf5=new FinanceDepartment("财务部"); 19 HRDepartment *leaf6=new HRDepartment("人力资源部"); 20 mid2->Add(leaf5); 21 mid2->Add(leaf6); 22 root->Add(mid2); 23 root->Show(0); 24 25 delete leaf1; delete leaf2; 26 delete leaf3; delete leaf4; 27 delete leaf5; delete leaf6; 28 delete mid1; delete mid2; 29 delete root; 30 return 0; 31 }
上面的实现方式有缺点，就是内存的释放不好，需要客户自己动手，非常不方便。有待改进，比较好的做法是让ConcreteCompany类来释放。因为所有的指针都是存在ConcreteCompany类的链表中。C++的麻烦，没有垃圾回收机制。
