图的深度优先遍历算法

      图的深度优先遍历类似于树的先根遍历，首先访问顶点v0，再访问v0的邻接点v1，同样递归访问v1的邻接点，若到vi时的所有邻接点均以访问完毕，则退回上一个顶点查看是否有邻接点为被访问，若有临界点w未被访问，则访问递归w，否则继续退回前一个结点。全部结点访问完毕时，算法结束。

      给出邻接表表示的图的递归和非递归算法，下面是图的邻接矩阵和邻接表表示，设置Visited[i]来记录结点i是否被访问。

#include 
#include 
#define MAXV 50

int visited[MAXV];

typedef int InfoType;

typedef struct 
{
	int no;
	InfoType info;
}VertType;

typedef struct
{
	int edges[MAXV][MAXV];
	VertType vexs[MAXV];
	int n,e;
}MGraph;

typedef struct ANode
{
	int adjvex;
	InfoType info;
	struct ANode *nextarc;
}ArcNode;

typedef int Vertex;

typedef struct
{
	Vertex data;
	ArcNode *firstarc;
}VNode;

typedef VNode AdjList[MAXV];

typedef struct
{
	AdjList adjlist;
	int n,e;
}ALGraph;

        递归算法如下：

void DFS(ALGraph *G,int v)
{
	ArcNode *p;
	int n=G->n;
	visited[v] = 1;
	printf("%3d",v);
	p = G->adjlist[v].firstarc;
	while(p)
	{
		if(visited[p->adjvex] == 0)
			DFS(G,p->adjvex);
		p = p->nextarc;
	}
}

        非递归算法如下：

void DFS1(ALGraph *G, int v)
{
	ArcNode *p;
	ArcNode *St[MAXV];
	int top=-1;
	int i,w,n=G->n;
	for(i=0; iadjlist[v].firstarc;
	while(top>=0)
	{
		p = St[top];
		top--;
		while(p!=NULL)
		{
			w = p->adjvex;
			if(visited[w] == 0)
			{
				visited[w] = 1;
				printf("%3d",w);
				top++;
				St[top] = G->adjlist[w].firstarc;
				break;		
			}
			p = p->nextarc;
		}
	}
}

void main()
{
	MGraph g;
	ALGraph *G;
	int i,j;
	int A[MAXV][6] = {
		{0,5,0,7,0,0},
		{0,0,4,0,0,0},
		{8,0,0,0,0,9},
		{0,0,5,0,0,6},
		{0,0,0,5,0,0},
		{3,0,0,0,1,0}
	};
	g.n = 6;
	g.e =10;
	for(i=0; i

      运行结果：