1 #include<cstdio>
  2 #include<vector>
  3 #include<cstring>
  4 using namespace std;
  5 
  6 vector<int>G[1005];
  7 bool flag;
  8 int low[1005],dfs_clock,pre[1005];
  9 bool iscut[1005];
 10 bool vis[1005];
 11 
 12 void init()
 13 {
 14     memset(iscut,0,sizeof(iscut));
 15     memset(pre,0,sizeof(pre));
 16     memset(vis,0,sizeof(vis));
 17     for(int i=0;i<1005;i++)G[i].clear();
 18     dfs_clock=0;
 19     flag=0;
 20 }
 21 
 22 int findcut(int u,int fa)
 23 {
 24     int lowu=pre[u]=++dfs_clock;
 25     int child=0;
 26     for(int i=0;i<G[u].size();i++)
 27     {
 28         int v=G[u][i];
 29         if(!pre[v])
 30         {
 31             child++;
 32             int lowv=findcut(v,u);
 33             lowu=min(lowu,lowv);
 34             if(lowv>=pre[u])
 35             iscut[u]=true;
 36         }
 37         else if(pre[v]<pre[u]&&v!=fa)
 38         lowu=min(lowu,pre[v]);
 39     }
 40     if(fa<0&&child==1)iscut[u]=0;
 41     low[u]=lowu;
 42     return lowu;
 43 }
 44 
 45 void dfs(int u)
 46 {
 47     vis[u]=1;
 48     for(int i=0;i<G[u].size();i++)
 49     if(!vis[G[u][i]])
 50     {
 51         vis[G[u][i]]=1;
 52         dfs(G[u][i]);
 53     }
 54 }
 55 
 56 void output()
 57 {
 58     for(int i=1;i<1005;i++)
 59     {
 60         if(iscut[i])
 61         {
 62             flag=1;
 63             memset(vis,0,sizeof(vis));
 64             vis[i]=1;
 65             int son=0;
 66             for(int j=0;j<G[i].size();j++)
 67             {
 68                 if(!vis[G[i][j]])
 69                 {
 70                     dfs(G[i][j]);
 71                     son++;
 72                 }
 73             }
 74             printf("  SPF node %d leaves %d subnets\n",i,son);
 75         }
 76     }
 77     if(!flag)
 78     printf("  No SPF nodes\n");
 79     printf("\n");
 80 }
 81 
 82 int main()
 83 {
 84     //freopen("in.txt","r",stdin);
 85     int u,v,t;
 86     bool key=0;
 87     t=0;
 88     while(scanf("%d",&u))
 89     {
 90         if(u==0&&key)
 91         break;
 92         else if(u==0&&!key)    
 93         {
 94             printf("Network #%d\n",++t);
 95             findcut(1,-1);
 96             output();
 97             init();
 98             key=1;
 99             continue;
100         }
101         if(u!=0)key=0;else key=1;
102         scanf("%d",&v);
103         G[u].push_back(v);
104         G[v].push_back(u);
105     }
106     return 0;
107 }