题目：http://acm.sdut.edu.cn/sdutoj/showproblem.php?pid=2142&cid=1186
1 #include<stdio.h> 2 #include<string.h> 3 #include<stdlib.h> 4 #include<iostream> 5 #include<queue> 6 using namespace std; 7 int vis[101]; 8 int n,m,k; 9 queue<int>q; 10 struct node 11 { 12 int u,v; 13 struct node *next; 14 }*head[110]; 15 void add(int u, int v) 16 { 17 struct node *p = (struct node*)malloc(sizeof(struct node)); 18 p->u = u; 19 p->v = v; 20 p->next = head[u]; 21 head[u] = p; 22 }; 23 int cmp(const void *a,const void *b) 24 { 25 return *(int *)a-*(int *)b; 26 } 27 void bfs(int t) 28 { 29 int i,x,a[110],j,b[110],y; 30 q.push(t); 31 vis[t]=1; j=0; 32 while(!q.empty()) 33 { 34 x=q.front(); 35 a[++j]=x; 36 q.pop(); 37 y=0; 38 for(struct node *p=head[x]; p!=NULL; p=p->next) 39 { 40 if(vis[p->v]==0) 41 { 42 b[y++]=p->v; 43 vis[p->v]=1; 44 } 45 } 46 if(y>=1) 47 qsort(b,y,sizeof(b[0]),cmp); 48 for(i=0; i<=y-1; i++) 49 q.push(b[i]); 50 } 51 for(i=1; i<=j-1; i++) 52 printf("%d ",a[i]); 53 printf("%d ",a[i]); 54 }; 55 int main() 56 { 57 int t,i,u,v; 58 scanf("%d",&n); 59 while(n--) 60 { 61 memset(head,NULL,sizeof(head)); 62 memset(vis,0,sizeof(vis)); 63 cin>>k>>m>>t; 64 for(i=0; i<m; i++) 65 { 66 cin>>u>>v; 67 add(u,v); 68 add(v,u); 69 } 70 bfs(t); 71 } 72 }