[设计模式] 设计模式课程（十七）--组合模式

 1 #include <iostream>
 2 #include <list>
 3 #include <string>
 4 #include <algorithm>
 5 
 6 using namespace std;
 7 
 8 class Component
 9 {
10 public:
11     virtual void process() = 0;
12     virtual ~Component(){}
13 };
14 
15 //树节点
16 class Composite : public Component{
17     
18     string name;
19     list<Component*> elements;
20 public:
21     Composite(const string & s) : name(s) {}
22     
23     void add(Component* element) {
24         elements.push_back(element);
25     }
26     void remove(Component* element){
27         elements.remove(element);
28     }
29     
30     void process(){
31         
32         //1. process current node
33         
34         //2. process leaf nodes
35         for (auto &e : elements)
36             e->process(); //多态调用
37          
38     }
39 };
40 
41 //叶子节点
42 class Leaf : public Component{
43     string name;
44 public:
45     Leaf(string s) : name(s) {}
46             
47     void process(){
48         //process current node
49     }
50 };
51 
52 void Invoke(Component & c){
53     //...
54     c.process();
55     //...
56 }
57 
58 int main()
59 {
60 
61     Composite root("root");
62     Composite treeNode1("treeNode1");
63     Composite treeNode2("treeNode2");
64     Composite treeNode3("treeNode3");
65     Composite treeNode4("treeNode4");
66     Leaf leat1("left1");
67     Leaf leat2("left2");
68     
69     root.add(&treeNode1);
70     treeNode1.add(&treeNode2);
71     treeNode2.add(&leaf1);
72     
73     root.add(&treeNode3);
74     treeNode3.add(&treeNode4);
75     treeNode4.add(&leaf2);
76     
77     process(root);
78     process(leaf2);
79     process(treeNode3);
80   
81 }