#include<stdio.h>
#define maxsize 100
typedef struct node{
  int data;
  struct node *next;
 }Node;
typedef struct adjnode{
  char ch[10];
  Node *firstarc;
 }Adjnode;
typedef struct q{
  int data[maxsize];
  int front,rear;
 }queue;
locate(Adjnode *adj,int n,char *s)
 {
  int i;
  for(i=0;i<n;i++)
   if(strcmp(adj[i].ch,s)==0)return i;
  return -1;
 }
createadj(Adjnode **adj,int n,int e)
 {char *s,*t; int i,j,k;
  Node *p,*q;
  printf("輸入各頂點(diǎn)的字符串.\n");
  for(i=0;i<n;i++)
   { gets(s);
    strcpy((*adj)[i].ch,s);
    (*adj)[i].firstarc=NULL;
   }
    printf("請(qǐng)輸入各條邊.\n");  /*如v1回車v2回車表明有v1到v2的邊*/
   for(i=1;i<=e;i++)
   {
    gets(s);
    gets(t);
    j=locate(*adj,n,s);
    k=locate(*adj,n,t);   
    if(k>=0 && j>=0){
     p=(Node *)malloc(sizeof(Node));
     p->data=k;p->next=NULL;
     q=(Node *)malloc(sizeof(Node));
     q->data=j;q->next=NULL;
     p->next=(*adj)[j].firstarc;
     (*adj)[j].firstarc=p;
     q->next=(*adj)[k].firstarc;
     (*adj)[k].firstarc=q;
     }
     else
     printf("邊的頂點(diǎn)輸入不正確!\n");
   }
 }
int *visited;
bfsadj(Adjnode *adj,int n)
 {
  Node *p;int i,j;queue q;
  q.front=q.rear=0;
   for(i=0;i<n;i++)
    visited[i]=0;
  for(i=0;i<n;i++)
   if(visited[i]==0){
    visited[i]=1;
    printf("==%s==\n",adj[i].ch);
    q.rear=(q.rear+1)%maxsize;
    q.data[q.rear]=i;
    while(q.front!=q.rear){
      q.front=(q.front+1)%maxsize;
      j=q.data[q.front];
       p=adj[j].firstarc; 
      while(p){
       if(visited[p->data]==0){
        visited[p->data]=1;
        printf("==%s==\n",adj[p->data].ch);
        q.rear=(q.rear+1)%maxsize;
        q.data[q.rear]=p->data;
        }
        p=p->next;
       }
      }
     }
  }
main()
{
 int n,e,i;
 Adjnode *adj;
 printf("輸入無(wú)向圖的頂點(diǎn)數(shù)和邊數(shù).\n");
 do
 scanf("%d%d",&n,&e);
 while(n<=0 || e<=0);
 getchar();
 adj=(Adjnode *)malloc(sizeof(Adjnode)*n);
 createadj(&adj,n,e);
 visited=(int *)malloc(sizeof(int)*n);
  bfsadj(adj,n);
  }