c++ 深度优先算法

#include <iostream>
using namespace std;

#define VertexNum 9  /*定义顶点数*/

struct Node    /*声明图形顶点结构*/
{
    int Vertex; /*邻接顶点数据*/
    struct Node *Next; /*下一个邻接顶点*/
};

typedef struct Node *Graph; /*定义图形结构*/
struct Node Head[VertexNum]; /*顶点数组*/
int Visited[VertexNum]; /*查找记录*/

/*深度优先算法*/
void DFS(int Vertex)
{
    Graph Pointer;
    
    Visited[Vertex]=1;//已查找
    cout<<Vertex<<"==>";
    Pointer=Head[Vertex].Next;
    
    while(Pointer!= NULL)
    {
      if(Visited[Pointer->Vertex]==0)
        DFS(Pointer->Vertex);
      Pointer=Pointer->Next;
    }
}

/*建立领接顶点至领接列表内*/
void Create_L_Graph(int Vertex1,int Vertex2)
{
    Graph Pointer;
    Graph New;
    
    New=(Graph)malloc(sizeof(struct Node));
    if(New!=NULL)
    {
      New->Vertex=Vertex2;
      New->Next=NULL;
      Pointer=&(Head[Vertex1]);
      while(Pointer->Next!=NULL)
        Pointer=Pointer->Next;
      Pointer->Next=New;
    }
}

/*输出领接列表内数据*/
void Print_L_Graph(struct Node *Head)
{
    Graph Pointer;
    Pointer=Head->Next;
    while(Pointer!=NULL)
    {
      cout<<"["<<Pointer->Vertex<<"]";
      Pointer=Pointer->Next;
    }
    cout<<endl;
}

/*主程序*/
void main()
{
    int Node[20][2]={{1,2},{2,1},{1,3},{3,1},{2,4},
    {4,2},{2,5},{5,2},{3,6},{6,3},
    {3,7},{7,3},{4,8},{8,4},{5,8},
    {8,5},{6,8},{8,6},{7,8},{8,7}    };
    
    for(int i=0;i<VertexNum;i++)
    {
      Head[i].Vertex=i;
      Head[i].Next=NULL;
    }    
    
    for(int i=0;i<VertexNum;i++)
      Visited[i]=0;
    
    for(int i=0;i<20;i++)
      Create_L_Graph(Node[i][0],Node[i][1]);

    cout<<"##Graph##"<<endl;
    for(int i=1;i<VertexNum;i++)
    {
      cout<<"Vertex["<<i<<"]:";
      Print_L_Graph(&Head[i]);      
    }

    cout<<"Depth-First-Search:"<<endl;
    cout<<"[BEGIN]==>";
    DFS(1);
    cout<<"END";

}