深度优先搜索树与广度优先搜索树

Posted 2021-03-05 yang901112

DFS使用c++中的stack，BFS使用c++中的queue

  1 #include <iostream>
  2 #define MAX_VERTS 20
  3 #include <stack>
  4 #include <queue>
  5 
  6 using namespace std;
  7 
  8 class Vertex
  9 {
 10 public:
 11     Vertex(char lab)
 12     {
 13         Label = lab;
 14         wasVisited = false;
 15     }
 16 
 17 public:
 18     bool wasVisited;
 19     char Label;
 20 };
 21 
 22 class Graph
 23 {
 24 public:
 25     Graph();
 26     ~Graph();
 27     void addVertex(char lab);
 28     void addEdge(int start, int End);
 29     void printMatrix();
 30     void showVertex(int v);
 31     void DFS();
 32     void BFS();
 33 private:
 34     Vertex *vertexList[MAX_VERTS];
 35     int nVerts;
 36     int adjMat[MAX_VERTS][MAX_VERTS];
 37     int getAdjUnivisitedVertex(int v);
 38 };
 39 
 40 void Graph::BFS()
 41 {
 42     queue<int> gQueue;
 43     vertexList[0]->wasVisited = true;
 44     showVertex(0);
 45     gQueue.push(0);
 46     int vert1, vert2;
 47     while(gQueue.size()>0)
 48     {
 49         vert1 = gQueue.front();
 50         gQueue.pop();
 51         vert2 = getAdjUnivisitedVertex(vert1);
 52         while(vert2 != -1)
 53         {
 54             vertexList[vert2]->wasVisited = true;
 55             showVertex(vert2);
 56             gQueue.push(vert2);
 57             vert2 = getAdjUnivisitedVertex(vert1);
 58         }
 59     }
 60     cout << endl;
 61     for(int j=0; j<nVerts; j++)
 62         vertexList[j]->wasVisited = false;
 63 }
 64 
 65 void Graph::DFS()
 66 {
 67     stack<int> gStack;
 68     vertexList[0]->wasVisited = true;
 69     showVertex(0);
 70     gStack.push(0);
 71     int v;
 72     while(gStack.size()>0)
 73     {
 74         v = getAdjUnivisitedVertex(gStack.top());
 75         if(v == -1)
 76             gStack.pop();
 77         else
 78         {
 79             vertexList[v]->wasVisited = true;
 80             showVertex(v);
 81             gStack.push(v);
 82         }
 83     }
 84     cout << endl;
 85     for(int j=0; j<nVerts; j++)
 86         vertexList[j]->wasVisited = false;
 87 }
 88 
 89 int Graph::getAdjUnivisitedVertex(int v)
 90 {
 91     for(int j=0; j<nVerts; j++)
 92         if((adjMat[v][j]==1) && (vertexList[j]->wasVisited==false))
 93             return j;
 94     return -1;
 95 }
 96 
 97 void Graph::showVertex(int v)
 98 {
 99     cout << vertexList[v]->Label << " ";
100 }
101 
102 Graph::Graph()
103 {
104     nVerts = 0;
105     for(int i=0; i<MAX_VERTS; i++)
106         for(int j=0; j<MAX_VERTS; j++)
107             adjMat[i][j] = 0;
108 }
109 
110 void Graph::addVertex(char lab)
111 {
112     vertexList[nVerts++] = new Vertex(lab);
113 }
114 
115 void Graph::addEdge(int start, int End)
116 {
117     adjMat[start][End] = 1;
118     adjMat[End][start] = 1;
119 }
120 
121 void Graph::printMatrix()
122 {
123     for(int i=0; i<nVerts; i++)
124     {
125         for(int j=0; j<nVerts; j++)
126             cout << adjMat[i][j] << " ";
127         cout << endl;
128     }
129 }
130 
131 Graph::~Graph()
132 {
133     for(int i=0; i<nVerts; i++)
134         delete vertexList[i];
135 }
136 
137 int main()
138 {
139 
140     Graph g;
141     g.addVertex(‘A‘);
142     g.addVertex(‘B‘);
143     g.addVertex(‘C‘);
144     g.addVertex(‘D‘);
145     g.addVertex(‘E‘);
146 
147     g.addEdge(0,1); // A-B
148     g.addEdge(0,3); // A-D
149     g.addEdge(1,0); // B-A
150     g.addEdge(1,4); // B-E
151     g.addEdge(2,4); // C-E
152     g.addEdge(3,0); // D-A
153     g.addEdge(3,4); // D-E
154     g.addEdge(4,1);
155     g.addEdge(4,2);
156     g.addEdge(4,3);
157     g.printMatrix();
158     cout << endl;
159 
160     cout << "深度优先搜索：" ;
161     g.DFS();
162     cout << endl;
163     cout << "广度优先搜索：" ;
164     g.BFS();
165     return 0;
166 }