【LA】5135 Mining Your Own Business

#include<cstdio>
#include<algorithm>
#include<vector>
#include<stack>
#include<cstring>
using namespace std;
const int maxm=50010;
struct edge{int u,v,from;}e[maxm*3];
int first[maxm],iscut[maxm],dfn[maxm],low[maxm],bccno[maxm],bcc_cnt,dfsnum,tot,n,m,kase;
vector<int>bcc[maxm];
stack<int>s;
void insert(int u,int v)
{tot++;e[tot].u=u;e[tot].v=v;e[tot].from=first[u];first[u]=tot;}
void tarjan(int x,int fa)
{
    dfn[x]=low[x]=++dfsnum;
    int child=0;
    for(int i=first[x];i;i=e[i].from)
     if(e[i].v!=fa)
      {
          int y=e[i].v;
//          s.push(i);
          if(!dfn[y])
           {
              s.push(i);//
              child++; //important
               tarjan(y,x);
               low[x]=min(low[x],low[y]);
               if(low[y]>=dfn[x])
                {
                    iscut[x]=1;
                    bcc_cnt++;
                    bcc[bcc_cnt].clear();
                    for(;;)
                     {
                         int now=s.top();s.pop();
                         int u=e[now].u,v=e[now].v;
                         if(bccno[u]!=bcc_cnt){bcc[bcc_cnt].push_back(u);bccno[u]=bcc_cnt;}
                         if(bccno[v]!=bcc_cnt){bcc[bcc_cnt].push_back(v);bccno[v]=bcc_cnt;}
//                         printf("%d\n",bcc_cnt);
                         if(u==x&&v==y)break;
                     }
                }
           }
          else if(dfn[y]<dfn[x])s.push(i),low[x]=min(low[x],dfn[y]);//important
      }
    if(fa<0&&child==1)iscut[x]=0;
}
int main()
{
    scanf("%d",&m);
    while(m!=0)
     {
         memset(first,0,sizeof(first));
         n=0;tot=0;bcc_cnt=0;
         for(int i=1;i<=m;i++)
          {
              int u,v;
              scanf("%d%d",&u,&v);
              n=max(n,max(u,v));
              insert(u,v);
              insert(v,u);
          }
         memset(dfn,0,sizeof(dfn));
         memset(low,0,sizeof(low));
         memset(iscut,0,sizeof(iscut));
         memset(bccno,0,sizeof(bccno));
         dfsnum=0;
         while(!s.empty())s.pop();
         for(int i=1;i<=n;i++)if(!dfn[i])tarjan(i,-1);
         long long ans1=0,ans2=1;
         for(int i=1;i<=bcc_cnt;i++)
          {
              int cut_cnt=0;
              for(int j=0;j<bcc[i].size();j++)
               if(iscut[bcc[i][j]])cut_cnt++;
              if(cut_cnt==1)
               {
                   ans1++;
                   ans2*=(long long)(bcc[i].size()-cut_cnt);
               }
          }
         if(bcc_cnt==1)
          {
              ans1=2;
              ans2=bcc[1].size()*(bcc[1].size()-1)/2;
          }
         printf("Case %d: %lld %lld\n",++kase,ans1,ans2);
         scanf("%d",&m);
     }
    return 0;
}