图的遍历

• 邻接矩阵的DFS

  const int MAXN = 100;
  bool visited[MAXN];
  
  struct MGraph
  {
  	int vexs[MAXN];//顶点表
  	int arc[MAXN][MAXN];//邻接矩阵
  	int numEdges, numVertexes;//边，点的数量
  };
  
  void DFS(MGraph *G,int i)
  {
  	int j;
  	visited[i] = 1;
  	cout << G->vexs << ' ';//输出节点信息也可以进行其他操作
  	for (j = 0; j < G->numVertexes; j++)
  		if (G->arc[i][j] == 1 && !visited[j])
  			DFS(G, j);
  }
  
  void DFSTraverse(MGraph *G)
  {
  	int i;
  	for (i = 0; i < G->numVertexes; i++)//初始化
  		visited[i] = 0;
  	for (i = 0; i < G->numVertexes; i++)
  		if (!visited[i])//未访问过的顶点调用DFS，若是连通图，则只执行一次
  			DFS(G, i);
  }
  

• 邻接表的DFS

  const int MAXN = 100;
  bool visited[MAXN];
  
  struct EdgeNode
  {
  	int adjvex;
  	EdgeNode *next;
  };
  
  struct VexNode
  {
  	int data;
  	EdgeNode *firstedge;
  };
  
  struct Grapha
  {
  	VexNode list[MAXN];
  	int numVertexes, numEdges;
  };
  
  void DFS(Grapha *G, int i)
  {
  	EdgeNode *p;
  	visited[i] = 1;
  	cout << G->list[i].data << ' ';//输出节点信息，也可以进行其他操作
  	p = G->list[i].firstedge;
  	while (p)
  	{
  		if (!visited[p->adjvex])
  			DFS(G, p->adjvex);
  		p = p->next;
  	}
  }
  
  void DFSTraverse(Grapha *G)
  {
  	for (int i = 0; i < G->numVertexes; i++)//初始化
  		visited[i] = 0;
  	for (int i = 0; i < G->numVertexes; i++)//若为连通图，只执行一次
  		if (!visited[i])
  			DFS(G, i);
  }
  

• 邻接矩阵的BFS

  const int MAXN = 1000;
  int visited[MAXN];
  
  struct MGraph
  {
  	int vexs[MAXN];//顶点表
  	int arc[MAXN][MAXN];//邻接矩阵
  	int numEdges, numVertexes;//边，点的数量
  };
  
  void BFSTraverse(MGraph G)
  {
  	int i, j;
  	queue<int>Q;
  	for (int i = 0; i < G.numVertexes; i++)
  		visited[i] = 0;
  	for (int i = 0; i < G.numVertexes; i++)
  	{
  		if (!visited[i])
  		{
  			visited[i] = 1;
  			cout << G.vexs[i] << ' ';
  			Q.push(i);
  			while (!Q.empty())
  			{
  				int t = Q.front();
  				Q.pop();
  				for (int j = 0; j < G.numVertexes; j++)
  				{
  					if (G.arc[t][j] == 1 && !visited[j])
  					{
  						visited[j] = 1;
  						cout << G.vexs[j] << ' ';
  						Q.push(j);
  					}
  				}
  			}
  		}
  	}
  }
  

• 邻接表的BFS

  const int MAXN = 1000;
  int visited[MAXN];
  
  struct EdgeNode			//边表节点
  {
  	int adjvex;//邻接点域(有向图中弧头下标)
  	EdgeNode *next;//指向下一个边表
  };
  struct VertexNode		//顶点表节点
  {
  	char data;//顶点域
  	EdgeNode *firstedge;//边表头指针
  };
  
  struct GraphAdjList//图
  {
  	VertexNode adjList[MAXN];//顶点表数组
  	int numVertexea, numEdges;//图中顶点数和边数
  };
  
  void BFSTraverse(GraphAdjList G)
  {
  	queue<int>Q;
  	for (int i = 0; i < G.numVertexea; i++)
  		visited[i] = 0;
  	for (int i = 0; i < G.numVertexea; i++)
  	{
  		if (!visited[i])
  		{
  			visited[i] = 1;
  			cout << G.adjList[i].data << ' ';
  			Q.push(i);
  			while (!Q.empty())
  			{
  				int t = Q.front();
  				Q.pop();
  				EdgeNode *p = G.adjList[t].firstedge;
  				while (p)
  				{
  					if (!visited[p->adjvex])
  					{
  						visited[p->adjvex] = 1;
  						cout << G.adjList[p->adjvex].data << ' ';
  						Q.push(p->adjvex);
  					}
  					p = p->next;
  				}
  			}
  		}
  	}
  }