第七十五课图的遍历（DFS）

添加DFS函数：

  1 #ifndef GRAPH_H
  2 #define GRAPH_H
  3 
  4 #include "Object.h"
  5 #include "SharedPointer.h"
  6 #include "Array.h"
  7 #include "DynamicArray.h"
  8 #include "LinkQueue.h"
  9 #include "LinkStack.h"
 10 
 11 namespace DTLib
 12 {
 13 
 14 template < typename E >
 15 struct Edge : public Object
 16 {
 17     int b;
 18     int e;
 19     E data;
 20 
 21     Edge(int i=-1, int j=-1)
 22     {
 23         b = i;
 24         e = j;
 25     }
 26 
 27     Edge(int i, int j, const E& value)
 28     {
 29         b = i;
 30         e = j;
 31         data = value;
 32     }
 33 
 34     bool operator == (const Edge<E>& obj)
 35     {
 36         return (b == obj.b) && (e == obj.e);  //在这里不关注权值大小
 37     }
 38 
 39     bool operator != (const Edge<E>& obj)
 40     {
 41         return !(*this == obj);
 42     }
 43 };
 44 
 45 template < typename V, typename E >
 46 class Graph : public Object
 47 {
 48 protected:
 49     template < typename T >
 50     DynamicArray<T>* toArray(LinkQueue<T>& queue)
 51     {
 52         DynamicArray<T>* ret = new DynamicArray<T>(queue.length());
 53 
 54         if( ret != NULL )
 55         {
 56             for(int i=0; i<ret->length(); i++, queue.remove())
 57             {
 58                 ret->set(i, queue.front());
 59             }
 60         }
 61         else
 62         {
 63             THROW_EXCEPTION(NoEnoughMemoryException, "No memory to create ret object...");
 64         }
 65 
 66         return ret;
 67     }
 68 public:
 69     virtual V getVertex(int i) = 0;
 70     virtual bool getVertex(int i, V& value) = 0;
 71     virtual bool setVertex(int i, const V& value) = 0;
 72     virtual SharedPointer< Array<int> > getAdjacent(int i) = 0;
 73     virtual E getEdge(int i, int j) = 0;
 74     virtual bool getEdge(int i, int j, E& value) = 0;
 75     virtual bool setEdge(int i, int j, const E& value) = 0;
 76     virtual bool removeEdge(int i, int j) = 0;
 77     virtual int vCount() = 0;
 78     virtual int eCount() = 0;
 79     virtual int OD(int i) = 0;
 80     virtual int ID(int i) = 0;
 81     virtual int TD(int i)
 82     {
 83         return ID(i) + OD(i);
 84     }
 85 
 86     SharedPointer< Array<int> > BFS(int i)
 87     {
 88         DynamicArray<int>* ret = NULL;
 89 
 90         if( (0 <= i) && (i < vCount()) )
 91         {
 92             LinkQueue<int> q;
 93             LinkQueue<int> r;
 94             DynamicArray<bool> visited(vCount());
 95 
 96             for(int i=0; i<visited.length(); i++)
 97             {
 98                 visited[i] = false;
 99             }
100 
101             q.add(i);
102 
103             while( q.length() > 0 )
104             {
105                 int v = q.front();
106 
107                 q.remove();
108 
109                 if( !visited[v] )
110                 {
111                     SharedPointer< Array<int> > aj = getAdjacent(v);
112 
113                     for(int j=0; j<aj->length(); j++)
114                     {
115                         q.add((*aj)[j]);
116                     }
117 
118                     r.add(v);
119 
120                     visited[v] = true;
121                 }
122             }
123 
124             ret = toArray(r);
125         }
126         else
127         {
128             THROW_EXCEPTION(InvalidParameterException, "Index i is invalid...");
129         }
130 
131         return ret;
132     }
133 
134     SharedPointer< Array<int> > DFS(int i)
135     {
136         DynamicArray<int>* ret = NULL;
137 
138         if( (0 <= i) && (i < vCount()) )
139         {
140             LinkStack<int> s;
141             LinkQueue<int> r;
142             DynamicArray<bool> visited(vCount());
143 
144             for(int j=0; j<visited.length(); j++)
145             {
146                 visited[j] = false;
147             }
148 
149             s.push(i);
150 
151             while( s.size() > 0 )
152             {
153                 int v = s.top();
154 
155                 s.pop();
156 
157                 if( !visited[v] )
158                 {
159                     SharedPointer< Array<int> > aj = getAdjacent(v);
160 
161                     for(int j=aj->length() - 1; j>=0; j--)
162                     {
163                         s.push((*aj)[j]);
164                     }
165 
166                     r.add(v);
167 
168                     visited[v] = true;
169                 }
170             }
171 
172             ret = toArray(r);
173         }
174         else
175         {
176             THROW_EXCEPTION(InvalidParameterException, "Index i is invalid...");
177         }
178 
179         return ret;
180     }
181 };
182 
183 }
184 
185 #endif // GRAPH_H

测试程序如下：

 1 #include <iostream>
 2 #include "BTreeNode.h"
 3 #include "ListGraph.h"
 4 #include "MatrixGraph.h"
 5 
 6 using namespace std;
 7 using namespace DTLib;
 8 
 9 
10 int main()
11 {
12     MatrixGraph<9, char, int> g;
13     const char* VD = "ABEDCGFHI";
14 
15     for(int i=0; i<9; i++)
16     {
17         g.setVertex(0, VD[i]);
18     }
19 
20     g.setEdge(0, 1, 0);
21     g.setEdge(1, 0, 0);
22 
23     g.setEdge(0, 3, 0);
24     g.setEdge(3, 0, 0);
25 
26     g.setEdge(0, 4, 0);
27     g.setEdge(4, 0, 0);
28 
29     g.setEdge(1, 2, 0);
30     g.setEdge(2, 1, 0);
31 
32     g.setEdge(1, 4, 0);
33     g.setEdge(4, 1, 0);
34 
35     g.setEdge(2, 5, 0);
36     g.setEdge(5, 2, 0);
37 
38     g.setEdge(3, 6, 0);
39     g.setEdge(6, 3, 0);
40 
41     g.setEdge(4, 6, 0);
42     g.setEdge(6, 4, 0);
43 
44     g.setEdge(6, 7, 0);
45     g.setEdge(7, 6, 0);
46 
47     g.setEdge(7, 8, 0);
48     g.setEdge(8, 7, 0);
49 
50     SharedPointer< Array<int> > sa = g.DFS(0);
51 
52     for(int i=0; i<sa->length(); i++)
53     {
54         cout << (*sa)[i] << " ";
55     }
56 
57     cout << endl;
58 
59     return 0;
60 }

结果如下：

深度优先的思想就是二叉树的先序遍历思想。

递归版的深入优先算法如下：

 1 #include <iostream>
 2 #include "BTreeNode.h"
 3 #include "ListGraph.h"
 4 #include "MatrixGraph.h"
 5 
 6 using namespace std;
 7 using namespace DTLib;
 8 
 9 template < typename V, typename E>
10 void DFS(Graph<V, E>& g, int v, Array<bool>& visited)
11 {
12     if( (0 <= v) && (v < g.vCount()) )
13     {
14         cout << v << endl;
15 
16         visited[v] = true;
17 
18         SharedPointer< Array<int> > aj = g.getAdjacent(v);
19 
20         for(int i=0; i<aj->length(); i++)
21         {
22             if( !visited[(*aj)[i]] )
23             {
24                 DFS(g, (*aj)[i], visited);
25             }
26         }
27     }
28     else
29     {
30         THROW_EXCEPTION(InvalidParameterException, "Index v is invalid...");
31     }
32 }
33 
34 template < typename V, typename E >
35 void DFS(Graph<V, E>& g, int v)
36 {
37     DynamicArray<bool> visited(g.vCount());
38 
39     for(int i=0; i<visited.length(); i++)
40     {
41         visited[i] = false;
42     }
43 
44     DFS(g, v, visited);
45 }
46 
47 int main()
48 {
49     MatrixGraph<9, char, int> g;
50     const char* VD = "ABEDCGFHI";
51 
52     for(int i=0; i<9; i++)
53     {
54         g.setVertex(0, VD[i]);
55     }
56 
57     g.setEdge(0, 1, 0);
58     g.setEdge(1, 0, 0);
59 
60     g.setEdge(0, 3, 0);
61     g.setEdge(3, 0, 0);
62 
63     g.setEdge(0, 4, 0);
64     g.setEdge(4, 0, 0);
65 
66     g.setEdge(1, 2, 0);
67     g.setEdge(2, 1, 0);
68 
69     g.setEdge(1, 4, 0);
70     g.setEdge(4, 1, 0);
71 
72     g.setEdge(2, 5, 0);
73     g.setEdge(5, 2, 0);
74 
75     g.setEdge(3, 6, 0);
76     g.setEdge(6, 3, 0);
77 
78     g.setEdge(4, 6, 0);
79     g.setEdge(6, 4, 0);
80 
81     g.setEdge(6, 7, 0);
82     g.setEdge(7, 6, 0);
83 
84     g.setEdge(7, 8, 0);
85     g.setEdge(8, 7, 0);
86 
87     SharedPointer< Array<int> > sa = g.DFS(0);
88 
89     for(int i=0; i<sa->length(); i++)
90     {
91         cout << (*sa)[i] << " ";
92     }
93 
94     cout << endl;
95 
96     DFS(g, 0);
97 
98     return 0;
99 }

结果如下：

小结：

第七十五课 图的遍历（DFS）

猜你喜欢

第七十五课图的遍历（DFS）