來自于《大話設計模式》
迭代器模式（Iterator）：提供一種方法順序訪問一個聚合對象中各個元素，而又不暴露該對象的內部表示。
UML 類圖：
代碼實現 C++：
1 #include <iostream>
2 #include <string>
3 using namespace std;
4
5 class Aggregate
6 {
7 private:
8 string data[100];
9 int index;
10 public:
11 Aggregate() : index(0){}
12 void push_back(const string& s)
13 {
14 data[index++] = s;
15 }
16 void push_pop()
17 {
18 --index;
19 }
20 string* getData()
21 {
22 return data;
23 }
24 int size()
25 {
26 return index;
27 }
28 };
29
30 class Iterator
31 {
32 private:
33 Aggregate* pAggr;
34 int current;
35 public:
36 Iterator(Aggregate& aggr)
37 {
38 pAggr = &aggr;
39 current = 0;
40 }
41 string First()
42 {
43 if (pAggr->size() > 0)
44 {
45 return (pAggr->getData())[0];
46 }
47 else
48 {
49 return "";
50 }
51 }
52 string End()
53 {
54 if (pAggr->size() > 0)
55 {
56 return (pAggr->getData())[pAggr->size() - 1];
57 }
58 else
59 {
60 return "";
61 }
62 }
63 void Next()
64 {
65 ++current;
66 }
67 bool IsDone()
68 {
69 return current == pAggr->size();
70 }
71 string CurrentItem()
72 {
73 if (pAggr->size() > 0)
74 {
75 return (pAggr->getData())[current];
76 }
77 else
78 {
79 return "";
80 }
81 }
82 void setBegin()
83 {
84 current = 0;
85 }
86 void setEnd()
87 {
88 current = pAggr->size();
89 }
90
91 void setRBegin()
92 {
93 current = pAggr->size() - 1;
94 }
95 void setREnd()
96 {
97 current = -1;
98 }
99 bool IsRDone()
100 {
101 return current == -1;
102 }
103 void RNext()
104 {
105 --current;
106 }
107 };
108
109 int main()
110 {
111 Aggregate aggr;
112 aggr.push_back("a");
113 aggr.push_back("b");
114 aggr.push_back("c");
115 aggr.push_back("d");
116 aggr.push_back("e");
117
118 Iterator iter(aggr);
119
120 while (!iter.IsDone())
121 {
122 cout << iter.CurrentItem() << ", hello!" << endl;
123 iter.Next();
124 }
125
126 iter.setBegin();
127 while (!iter.IsDone())
128 {
129 cout << iter.CurrentItem() << ", bye!" << endl;
130 iter.Next();
131 }
132
133
134 iter.setRBegin();
135 while (!iter.IsRDone())
136 {
137 cout << iter.CurrentItem() << ", reverse!" << endl;
138 iter.RNext();
139 }
140
141 iter.setBegin();
142
143 return 0;
144 }
posted @
2011-04-29 16:52 unixfy 閱讀(222) |
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編輯 收藏
來自于《大話設計模式》
組合模式（Composite）：將對象組合成樹形結構以表示‘部分-整體’的層次結構。組合模式使得用戶對單個對象和組合對象的使用具有一致性。
UML 類圖：
代碼實現 C++：
1 #include <iostream>
2 #include <string>
3 #include <list>
4 #include <algorithm>
5 using namespace std;
6
7 class Company
8 {
9 protected:
10 string name;
11 public:
12 Company(const string& s) : name(s) {}
13 virtual void Add(Company* c) = 0;
14 virtual void Remove(Company* c) = 0;
15 virtual void Display(int depth) = 0;
16 virtual void LineOfDuty() = 0;
17 };
18
19 class ConcreteCompany : public Company
20 {
21 private:
22 list<Company*> children;
23 public:
24 ConcreteCompany(const string& s) : Company(s) {}
25 virtual void Add(Company* c)
26 {
27 children.push_back(c);
28 }
29 virtual void Remove(Company* c)
30 {
31 list<Company*>::iterator iter = find(children.begin(), children.end(), c);
32 if (iter != children.end())
33 {
34 children.erase(iter);
35 }
36 }
37 virtual void Display(int depth)
38 {
39 string str(depth, '-');
40 str += name;
41 cout << str << endl;
42 for (list<Company*>::iterator iter = children.begin(); iter != children.end(); ++iter)
43 {
44 (*iter)->Display(depth + 2);
45 }
46 }
47 virtual void LineOfDuty()
48 {
49 for (list<Company*>::iterator iter = children.begin(); iter != children.end(); ++iter)
50 {
51 (*iter)->LineOfDuty();
52 }
53 }
54 };
55
56 class HRDepartment : public Company
57 {
58 public:
59 HRDepartment(const string& s) : Company(s) {}
60 virtual void Add(Company* c) {}
61 virtual void Remove(Company* c) {}
62 virtual void Display(int depth)
63 {
64 string str(depth, '-');
65 str += name;
66 cout << str << endl;
67 }
68 virtual void LineOfDuty()
69 {
70 cout << name << " 員工招聘培訓管理！" << endl;
71 }
72 };
73
74 class FinanceDepartment : public Company
75 {
76 public:
77 FinanceDepartment(const string& s) : Company(s) {}
78 virtual void Add(Company* c) {}
79 virtual void Remove(Company* c) {}
80 virtual void Display(int depth)
81 {
82 string str(depth, '-');
83 str += name;
84 cout << str << endl;
85 }
86 virtual void LineOfDuty()
87 {
88 cout << name << " 公司財務收支管理！" << endl;
89 }
90 };
91
92 int main()
93 {
94 ConcreteCompany root("北京總公司");
95 root.Add(new HRDepartment("總公司人力資源部"));
96 root.Add(new FinanceDepartment("總公司財務部"));
97
98 ConcreteCompany* comp = new ConcreteCompany("上海華東分公司");
99 comp->Add(new HRDepartment("華東分公司人力資源部"));
100 comp->Add(new FinanceDepartment("華東分公司財務部"));
101 root.Add(comp);
102
103 ConcreteCompany* comp2 = new ConcreteCompany("南京辦事處");
104 comp2->Add(new HRDepartment("南京辦事處人力資源部"));
105 comp2->Add(new FinanceDepartment("南京辦事處財務部"));
106 root.Add(comp2);
107
108 ConcreteCompany* comp3 = new ConcreteCompany("杭州辦事處");
109 comp3->Add(new HRDepartment("杭州辦事處人力資源部"));
110 comp3->Add(new FinanceDepartment("杭州辦事處財務部"));
111 root.Add(comp3);
112
113 cout << "結構圖:" << endl;
114 root.Display(1);
115
116 cout << "職責：" << endl;
117 root.LineOfDuty();
118
119 return 0;
120 }
posted @
2011-04-29 16:14 unixfy 閱讀(235) |
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備忘錄模式（Memento）：在不破壞封裝性的前提下，捕獲一個對象的內部狀態，并在該對象之外保存這個狀態。這樣以后就可以將該對象恢復到原先保存的狀態。
UML 類圖：
代碼實現 C++：
1 #include <iostream>
2 using namespace std;
3
4 class RoleStateMemento
5 {
6 public:
7 int vit;
8 int atk;
9 int def;
10 public:
11 RoleStateMemento(int v = 0, int a = 0, int d = 0) : vit(v), atk(a), def(d) {}
12 };
13
14 class Roles
15 {
16 private:
17 int vit;
18 int atk;
19 int def;
20 public:
21 Roles(int v = 100, int a = 100, int d = 100) : vit(v), atk(a), def(d) {}
22 void getInitState()
23 {
24 vit = 100;
25 atk = 100;
26 def = 100;
27 }
28 void fight()
29 {
30 vit = 0;
31 atk = 0;
32 def = 0;
33 }
34 void displayState()
35 {
36 cout << "體力：" << vit << endl;
37 cout << "攻擊力：" << atk << endl;
38 cout << "防御力：" << def << endl;
39 }
40 RoleStateMemento SaveState()
41 {
42 return RoleStateMemento(vit, atk, def);
43 }
44 void RecoveryState(const RoleStateMemento& memento)
45 {
46 vit = memento.vit;
47 atk = memento.atk;
48 def = memento.def;
49 }
50 };
51
52 class RoleStateCaretaker
53 {
54 private:
55 public:
56 RoleStateMemento memento;
57 };
58
59 int main()
60 {
61 Roles* r = new Roles;
62 r->getInitState();
63 r->displayState();
64
65 RoleStateCaretaker* stateAdmin = new RoleStateCaretaker;
66 stateAdmin->memento = r->SaveState();
67
68 r->fight();
69 r->displayState();
70
71 r->RecoveryState(stateAdmin->memento);
72 r->displayState();
73
74 return 0;
75 }
posted @
2011-04-29 08:43 unixfy 閱讀(140) |
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編輯 收藏隱式類型轉換，其他類型的變量可以通過構造函數隱式轉換為一個類類型的對象，這里隱式轉換會產生一個無名的臨時對象，這個對象是常量不能被修改。所以說，不能將其賦值給一個非 const 的引用，這樣編譯不通過，最好是賦值給 const 型的引用 const T&。也可以賦值給 值類型，const、非 const 都行，但是這種效率不高。
這里只需注意通過隱式類型轉換產生的臨時對象是無名的常量對象。
通過隱式類型轉換產生的臨時對象和通過函數返回值返回的一個臨時的無名對象不同。通過函數返回的臨時對象，可以是常量也可以是變量。如果是變量，我們還可以修改這個無名的變量，雖然這樣做沒有意義，一般情況下有副作用。因為本該修改的沒有得到修改。
通過函數返回值得到的無名的臨時對象是否具有常量性，是由函數的返回值類型決定的。是有程序員自己定義函數的時候決定的。而隱式類型轉換生成的無名的臨時對象的常量性是由編譯器自動決定的，與程序員無關。
防止隱式類型轉換可以通過 explicit 關鍵字。
class T
{
public:
T(int a = 1, int b = 2) {
}
};
T t;
t = 5;
這樣是首先 5 轉換為一個無名的常量性臨時對象，然后復制給 t，這里用的賦值運算符是編譯器提供的默認 operator =。其形參類型為 const T&。
如果程序員自己提供了 operator =，并且形參類型為 T& 而非 const T&。這樣編譯就會報錯。因為不能將常量復制給 非 const 引用。只是由 C++ 的語法決定的。
一般情況下，如果不改變實參，在定義函數的時候都盡量將形參類型聲明為 const T&。這樣做的好處是效率高，并且避免不必要的麻煩。這是一種最為可靠和安全的方法。
另外，隱式類型轉換和類型轉換操作符在一起的時候還容易產生二義性。這種情況下，最好針對各種不同的參數類型，進行各種重載。但是還要考慮模板帶來的二義性等。
posted @
2011-04-29 00:56 unixfy 閱讀(291) |
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編輯 收藏
設計一個長方形類Triangle，包含長和寬兩個私有數據成員。
要求重載運算符
·=
能夠支持：對象=數值 普通變量=對象 對象=對象 支持連續的賦值
·+= ：自定義加法功能
聯系與=的聯系
·> ：實現比較兩個矩形對象面積大小的比較
能夠支持：兩個對象的比較，對象和數字的比較，數字和對象的比較
·>> ：實現矩形對象的輸入
·<< ：實現矩形對象的輸出
1 #include <iostream>
2 using namespace std;
3
4 class Triangle
5 {
6 private:
7 double length;
8 double width;
9 public:
10 Triangle(double l = 0.0, double w = 0.0) : length(l), width(w) {}
11 ~Triangle() {}
12 Triangle(const Triangle& t) : length(t.length), width(t.width) {}
13 Triangle& operator =(const Triangle& t)
14 {
15 if (this != &t)
16 {
17 length = t.length;
18 width = t.width;
19 }
20 return *this;
21 }
22 Triangle& operator =(double d)
23 {
24 length = width = d;
25 return *this;
26 }
27 operator double ()
28 {
29 return length * width;
30 }
31 Triangle& operator +=(const Triangle& t)
32 {
33 length += t.length;
34 width += t.width;
35 return *this;
36 }
37 friend bool operator > (const Triangle& lhs, const Triangle& rhs);
38 friend bool operator > (const Triangle& lhs, double rhs);
39 friend bool operator > (double lhs, const Triangle& rhs);
40 friend istream& operator >>(istream& in, Triangle& rhs);
41 friend ostream& operator <<(ostream& out, const Triangle& rhs);
42 };
43
44 bool operator >(const Triangle& lhs, const Triangle& rhs)
45 {
46 return lhs.length * lhs.width > rhs.length * rhs.width;
47 }
48
49 bool operator >(const Triangle& lhs, double rhs)
50 {
51 return lhs.length * lhs.width > rhs;
52 }
53
54 bool operator >(double lhs, const Triangle& rhs)
55 {
56 return lhs > rhs.length * rhs.width;
57 }
58
59 istream& operator >>(istream& in, Triangle& rhs)
60 {
61 in >> rhs.length >> rhs.width;
62 if (!in)
63 {
64 cerr << "Input error!" << endl;
65 exit(1);
66 }
67 return in;
68 }
69
70 ostream& operator <<(ostream& out, const Triangle& rhs)
71 {
72 out << rhs.length << '\t' << rhs.width;
73 return out;
74 }
75
76 Triangle& operator +(const Triangle& lhs, const Triangle& rhs)
77 {
78 Triangle tmp(lhs);
79 return tmp += rhs;
80 }
81
82 int main()
83 {
84 Triangle t1(1.0, 2.0);
85 Triangle t2;
86 t1 = t2;
87
88 cin >> t1 >> t2;
89 cout << t1 << endl;
90 cout << t2 << endl;
91
92 t1 = t2;
93 cout << t1 << endl;
94 cout << t2 << endl;
95
96 t1 = 10.0;
97 cout << t1 << endl;
98 double d = 0.0;
99 d = t1;
100 cout << d << endl;
101
102 cout << (t1 > t2) << endl;
103 cout << (t1 > 5.0) << endl;
104 cout << (5.0 > t1) << endl;
105
106 t1 += t2;
107 cout << t1 << endl;
108 cout << t2 << endl;
109
110 return 0;
111 }
posted @
2011-04-29 00:40 unixfy 閱讀(202) |
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編輯 收藏單鏈表的逆轉
帶頭結點的單鏈表
一種方法是判斷是否沒有數據節點、只有一個數據節點。這種情況不翻轉，在翻轉循環里還要判斷是否只有是第一個結點，如果是則將該結點的 next 置為 0。
一種效率更好的方式是：
void reverse(Node* head)
{
Node* p1, *p2, *p3;
p1 = p2 = 0;
p3 = head->next;
while (p3 != 0)
{
p2 = p3;
p3 = p3->next;
p2->next = p1;
p1 = p2;
}
head->next = p2;
}
這種方式即包括了沒有數據節點、只有一個數據節點的情況，也可以處理將第一個結點的 next 置為 0 的情況。
所以這種方式既明確效率也更高。
1 #include <iostream>
2 using namespace std;
3
4 template <typename T>
5 class Link
6 {
7 public:
8 template <typename T>
9 struct Node
10 {
11 T data;
12 Node<T>* next;
13 };
14 private:
15 Node<T>* head;
16 public:
17 Link()
18 {
19 head = new Node<T>;
20 head->next = 0;
21 }
22 ~Link()
23 {
24 Node<T>* p = head->next, *q = 0;
25 while (p != 0)
26 {
27 q = p->next;
28 delete p;
29 p = q;
30 }
31 delete head;
32 }
33 Node<T>* Head()
34 {
35 return head;
36 }
37 void insert(T item, Node<T>* p)
38 {
39 Node<T>* q = new Node<T>;
40 q->next = p->next;
41 q->data = item;
42 p->next = q;
43 }
44
45 void reverse()
46 {
47 Node<T>* p1, *p2, *p3;
48 p1 = p2 = 0;
49 p3 = head->next;
50 while (p3 != 0)
51 {
52 p2 = p3;
53 p3 = p3->next;
54 p2->next = p1;
55 p1 = p2;
56 }
57 head->next = p2;
58 }
59
60 // friend template <typename T> ostream& operator <<(ostream& out, Link<T>& link);
61 };
62
63 template <typename T>
64 ostream& operator <<(ostream& out, Link<T>& link)
65 {
66 const Link<T>::Node<T>* p = link.Head()->next;
67 while (p)
68 {
69 out << p->data << ' ';
70 p = p->next;
71 }
72 return out;
73 }
74
75 int main()
76 {
77 Link<int> link;
78 for (int i = 0; i < 10; ++i)
79 {
80 link.insert(i, link.Head());
81 }
82 cout << link << endl;
83
84 link.reverse();
85
86 cout << link << endl;
87 }
posted @
2011-04-29 00:13 unixfy 閱讀(295) |
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編輯 收藏適配器模式（Adapter）：將一個類的接口轉換成客戶希望的另外一個接口。Adapter 模式使得原本由于接口不兼容而不能在一起工作的那些類可以一起工作。
結構型
·類
·對象
UML 類圖：
代碼實現 C++：
1 #include <iostream>
2 #include <string>
3 using namespace std;
4
5 class Player
6 {
7 protected:
8 string name;
9 public:
10 Player(const string& s = "") : name(s) {}
11 virtual void Attack() = 0;
12 virtual void Defense() = 0;
13 };
14
15 class Forwards : public Player
16 {
17 public:
18 Forwards(const string& s = "") : Player(s) {}
19 virtual void Attack()
20 {
21 cout << "前鋒 " << name << " 進攻！" << endl;
22 }
23 virtual void Defense()
24 {
25 cout << "前鋒 " << name << " 防守！" << endl;
26 }
27 };
28
29 class Center : public Player
30 {
31 public:
32 Center(const string& s = "") : Player(s) {}
33 virtual void Attack()
34 {
35 cout << "中鋒 " << name << " 進攻！" << endl;
36 }
37 virtual void Defense()
38 {
39 cout << "中鋒 " << name << " 防守！" << endl;
40 }
41 };
42
43 class Guards : public Player
44 {
45 public:
46 Guards(const string& s) : Player(s) {}
47 virtual void Attack()
48 {
49 cout << "后衛 " << name << " 進攻！" << endl;
50 }
51 virtual void Defense()
52 {
53 cout << "后衛 " << name << " 防守！" << endl;
54 }
55 };
56
57 class ForeignCenters
58 {
59 private:
60 string name;
61 public:
62 ForeignCenters(const string& s = "") : name(s) {}
63 void ForeignAttack()
64 {
65 cout << "外籍中鋒 " << name << " 進攻！" << endl;
66 }
67 void ForeignDefense()
68 {
69 cout << "外籍中鋒 " << name << " 防守！" << endl;
70 }
71 };
72
73 class Translators : public Player
74 {
75 private:
76 ForeignCenters* fc;
77 public:
78 Translators(const string& s = "", const string& f = "") : Player(s), fc(new ForeignCenters(f)) {}
79 ~Translators()
80 {
81 delete fc;
82 }
83 virtual void Attack()
84 {
85 fc->ForeignAttack();
86 }
87 virtual void Defense()
88 {
89 fc->ForeignDefense();
90 }
91 };
92
93 int main()
94 {
95 Player* b = new Forwards("巴蒂爾");
96 b->Attack();
97 b->Defense();
98
99 Player* m = new Guards("麥克格雷迪");
100 m->Attack();
101 m->Defense();
102
103 Player* y = new Translators("翻譯者", "姚明");
104 y->Attack();
105 y->Defense();
106
107 return 0;
108 }
posted @
2011-04-28 14:31 unixfy 閱讀(120) |
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來自于《大話設計模式》
狀態模式（State）：當一個對象的內在狀態改變時允許改變其行為，這個對象看起來像是改變了其類。
UML 類圖：
代碼實現 C++：
1 #include <iostream>
2 using namespace std;
3
4 class Work;
5 class State;
6 double getHour(Work* w);
7 void setState(Work * w, State * s);
8 bool getFinish(Work* w);
9 void WriteProgramOutside(Work * w);
10
11 class State
12 {
13 public:
14 virtual void WriteProgram(Work * w) = 0;
15 };
16
17 class RestState : public State
18 {
19 public:
20 virtual void WriteProgram(Work * w)
21 {
22 cout << "當前時間：" << getHour(w) << " 點下班回家了。" << endl;
23 }
24 };
25
26 class SleepingState : public State
27 {
28 public:
29 virtual void WriteProgram(Work * w)
30 {
31 cout << "當前時間：" << getHour(w) << " 點不行了，睡著了。" << endl;
32 }
33 };
34
35 class EveningState : public State
36 {
37 public:
38 virtual void WriteProgram(Work * w)
39 {
40 if (getFinish(w))
41 {
42 setState(w, static_cast<State*>(new RestState));
43 WriteProgramOutside(w);
44 }
45 else
46 {
47 if (getHour(w) < 21.0)
48 {
49 cout << "當前時間：" << getHour(w) << " 點 加班哦，疲憊之極。" << endl;
50 }
51 else
52 {
53 setState(w, new SleepingState);
54 WriteProgramOutside(w);
55 }
56 }
57 }
58 };
59
60 class AfternoonState : public State
61 {
62 public:
63 virtual void WriteProgram(Work * w)
64 {
65 if (getHour(w) < 17.0)
66 {
67 cout << "當前時間：" << getHour(w) << " 點 下午狀態還不錯，繼續努力。" << endl;
68 }
69 else
70 {
71 setState(w, new EveningState);
72 WriteProgramOutside(w);
73 }
74 }
75 };
76
77 class NoonState : public State
78 {
79 public:
80 virtual void WriteProgram(Work * w)
81 {
82 if (getHour(w) < 13.0)
83 {
84 cout << "當前時間：" << getHour(w) << " 點 餓了，午飯；犯困，午休。" << endl;
85 }
86 else
87 {
88 setState(w, new AfternoonState);
89 WriteProgramOutside(w);
90 }
91 }
92 };
93
94 class ForenoonState : public State
95 {
96 public:
97 virtual void WriteProgram(Work* w)
98 {
99 if (getHour(w) < 12.0)
100 {
101 cout << "當前時間：" << getHour(w) << " 點 上午工作，精神百倍！" << endl;
102 }
103 else
104 {
105 setState(w, new NoonState);
106 WriteProgramOutside(w);
107 }
108 }
109 };
110
111 class Work
112 {
113 private:
114 State * current;
115 double hour;
116 bool finish;
117 public:
118 double getHour()
119 {
120 return hour;
121 }
122 void setHour(double h)
123 {
124 hour = h;
125 }
126 bool getFinish()
127 {
128 return finish;
129 }
130 void setFinsh(bool f)
131 {
132 finish = f;
133 }
134 void setState(State * w)
135 {
136 delete current;
137 current = w;
138 }
139 void WriteProgram()
140 {
141 current->WriteProgram(this);
142 }
143 Work()
144 {
145 current = new ForenoonState;
146 finish = false;
147 }
148 ~Work()
149 {
150 delete current;
151 }
152 };
153
154 double getHour(Work * w)
155 {
156 return w->getHour();
157 }
158 void setHour(Work * w, double h)
159 {
160 w->setHour(h);
161 }
162 bool getFinish(Work * w)
163 {
164 return w->getFinish();
165 }
166 void setFinish(Work * w, bool f)
167 {
168 w->setFinsh(f);
169 }
170 void setState(Work * w, State * s)
171 {
172 w->setState(s);
173 }
174
175 void WriteProgramOutside(Work * w)
176 {
177 w->WriteProgram();
178 }
179
180 int main()
181 {
182 Work* emergencyProjects = new Work;
183 emergencyProjects->setHour(9.0);
184 emergencyProjects->WriteProgram();
185 emergencyProjects->setHour(10.0);
186 emergencyProjects->WriteProgram();
187 emergencyProjects->setHour(12.0);
188 emergencyProjects->WriteProgram();
189 emergencyProjects->setHour(13.0);
190 emergencyProjects->WriteProgram();
191 emergencyProjects->setHour(14.0);
192 emergencyProjects->WriteProgram();
193 emergencyProjects->setHour(17.0);
194 emergencyProjects->WriteProgram();
195
196 // emergencyProjects->setFinsh(true);
197 emergencyProjects->setFinsh(false);
198
199 emergencyProjects->WriteProgram();
200 emergencyProjects->setHour(19.0);
201 emergencyProjects->WriteProgram();
202 emergencyProjects->setHour(22.0);
203 emergencyProjects->WriteProgram();
204
205 delete emergencyProjects;
206 return 0;
207 }
posted @
2011-04-27 16:39 unixfy 閱讀(216) |
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來自于《大話設計模式》
抽象工廠模式（Abstract Factory）：提供一個創建一系列相關或相互依賴對象的接口，而無需指定它們具體的類。
UML 類圖：
代碼實現 C++：
1 #include <iostream>
2 #include <string>
3 using namespace std;
4
5 class IUser
6 {
7 public:
8 virtual void insert(const string& s) = 0;
9 virtual string getUser(int id) = 0;
10 };
11
12 class SqlserverUser : public IUser
13 {
14 public:
15 virtual void insert(const string& s)
16 {
17 cout << "SqlserverUser::insert " << s << endl;
18 }
19 virtual string getUser(int id)
20 {
21 cout << "SqlserverUser::getUser " << id << endl;
22 return "";
23 }
24 };
25
26 class AccessUser : public IUser
27 {
28 public:
29 virtual void insert(const string& s)
30 {
31 cout << "AccessUser::insert " << s << endl;
32 }
33 virtual string getUser(int id)
34 {
35 cout << "AccessUser::getUser " << id << endl;
36 return "";
37 }
38 };
39
40 class IDepartment
41 {
42 public:
43 virtual void insert(const string& s) = 0;
44 virtual string getDepartment(int id) = 0;
45 };
46
47 class SqlserverDepartment : public IDepartment
48 {
49 public:
50 virtual void insert(const string& s)
51 {
52 cout << "SqlserverDepartment::insert " << s << endl;
53 }
54 virtual string getDepartment(int id)
55 {
56 cout << "SqlserverDepartment::getDepartment " << id << endl;
57 return "";
58 }
59 };
60
61 class AccessDepartment : public IDepartment
62 {
63 public:
64 virtual void insert(const string& s)
65 {
66 cout << "AccessDepartment::insert " << s << endl;
67 }
68 virtual string getDepartment(int id)
69 {
70 cout << "AccessDepartment::getDepartment " << id << endl;
71 return "";
72 }
73 };
74
75 class IFactory
76 {
77 public:
78 virtual IUser * CreateUser() = 0;
79 virtual IDepartment * CreateDepartment() = 0;
80 };
81
82 class SqlserverFactory : public IFactory
83 {
84 public:
85 virtual IUser * CreateUser()
86 {
87 return new SqlserverUser;
88 }
89 virtual IDepartment* CreateDepartment()
90 {
91 return new SqlserverDepartment;
92 }
93 };
94
95 class AccessFactory : public IFactory
96 {
97 public:
98 virtual IUser * CreateUser()
99 {
100 return new AccessUser;
101 }
102 virtual IDepartment * CreateDepartment()
103 {
104 return new AccessDepartment;
105 }
106 };
107
108 int main()
109 {
110 string user = "abc";
111 string department = "xyz";
112
113 IFactory * factory = new AccessFactory;
114 IUser * iu = factory->CreateUser();
115 iu->insert(user);
116 iu->getUser(1);
117 IDepartment * id = factory->CreateDepartment();
118 id->insert(department);
119 id->getDepartment(1);
120 delete factory;
121 delete iu;
122 delete id;
123
124 factory = new SqlserverFactory;
125 iu = factory->CreateUser();
126 iu->insert(user);
127 iu->getUser(1);
128 id = factory->CreateDepartment();
129 id->insert(department);
130 id->getDepartment(1);
131 delete factory;
132 delete iu;
133 delete id;
134
135 return 0;
136 }
posted @
2011-04-27 14:53 unixfy 閱讀(506) |
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單鏈表的逆轉，關鍵在于三個輔助指針，前兩個指針用于逆轉，最后一個用于記錄剩下來的節點，不然鏈表就丟失了。
這里是用的帶頭結點的鏈表，考慮鏈表中沒有節點和只有一個節點的情況就不用逆轉了。
1 #include <iostream>
2 using namespace std;
3
4 struct node
5 {
6 int data;
7 node * next;
8 };
9
10 node * init()
11 {
12 node * head = new node;
13 if (head == 0)
14 {
15 exit(1);
16 }
17 head->next = 0;
18 return head;
19 }
20
21 node * insert(int item, node * pre)
22 {
23 node * tmp = new node;
24 if (tmp == 0)
25 {
26 exit(1);
27 }
28 tmp->data = item;
29 tmp->next = pre->next;
30 pre->next = tmp;
31 return tmp;
32 }
33
34 node * create(node * head)
35 {
36 for (int i = 0; i < 10; ++i)
37 {
38 insert(i, head);
39 }
40 return head;
41 }
42
43 node * reverse(node * head)
44 {
45 node * p1 = head->next;
46 if (p1 == 0)
47 {
48 return head;
49 }
50
51 node * p2 = p1->next;
52 if (p2 == 0)
53 {
54 return head;
55 }
56
57 node * p3;
58
59 while (p2 != 0)
60 {
61 p3 = p2->next;
62 p2->next = p1;
63 if (p1 == head->next)
64 {
65 p1->next = 0;
66 }
67 p1 = p2;
68 p2 = p3;
69 }
70 head->next = p1;
71 return head;
72 }
73
74 void clear_(node * head)
75 {
76 node * p = head->next, * q;
77 while (p != 0)
78 {
79 q = p->next;
80 delete p;
81 p = q;
82 }
83 head->next = 0;
84 }
85
86 void clear(node * head)
87 {
88 clear_(head);
89 delete head;
90 }
91
92 node * copy(node * des, node * src)
93 {
94 clear_(des);
95 node * p = src->next, * q, * d = des;
96 while (p != 0)
97 {
98 q = new node;
99 q->data = p->data;
100 q->next = 0;
101 d->next = q;
102 d = q;
103 p = p->next;
104 }
105 return des;
106 }
107
108 void print(node * head)
109 {
110 node * p = head->next;
111 while (p != 0)
112 {
113 cout << p->data << ' ';
114 p = p->next;
115 }
116 cout << endl;
117 }
118
119 int main()
120 {
121 node * t1 = init();
122 create(t1);
123 print(t1);
124
125 node * t2 = init();
126 copy(t2, t1);
127 print(t2);
128 reverse(t2);
129 print(t2);
130
131 return 0;
132 }
posted @
2011-04-27 13:48 unixfy 閱讀(475) |
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