BZOJ 2730 矿场搭建（割点）

map<int,int> mp;
int n,m;
vector<int> g[N];
int dfn[N],low[N],cut[N],id;
int visit[N];


void DFS(int u,int pre)
{
    dfn[u]=low[u]=++id; visit[u]=1; 
    int cnt=0,i,v;
    FOR0(i,SZ(g[u]))
    {
        v=g[u][i];
        if(v==pre) continue;
        if(!dfn[v])
        {
            DFS(v,u); cnt++; upMin(low[u],low[v]);
            if(dfn[u]<=low[v]&&pre!=-1) cut[u]=1;
        }
        else upMin(low[u],dfn[v]);
    }
    if(cnt>1&&pre==-1) cut[u]=1;
}


int S[N],color,p[N],mark[N];


void dfs(int u)
{
    visit[u]=1; S[color]++;
    int i,v;
    FOR0(i,SZ(g[u]))
    {
        v=g[u][i];
        if(!visit[v])
        {
            if(!cut[v]) dfs(v);
            else if(mark[v]!=color)
            {
                mark[v]=color;
                p[color]++;
            }
        }
    }
}


void deal()
{
    clr(visit,0); clr(S,0); clr(p,0); clr(mark,0);
    i64 ans=1,cnt=0;
    int i;
    color=0;
    FOR1(i,m) if(!visit[i]&&!cut[i])
    {
        color++; dfs(i);
        if(p[color]==1) cnt++,ans*=S[color];
    }
    if(color==1) cnt=2,ans=m*(m-1)/2;
    printf("%lld %lld\n",cnt,ans);
}


int main()
{
    int num=0;
    Rush(n)
    {
        if(!n) break;
        int i;
        FOR1(i,n+n) g[i].clear();
        mp.clear();
        int x,y;
        m=0;
        FOR1(i,n)
        {
            RD(x,y);
            if(!mp.count(x)) mp[x]=++m;
            if(!mp.count(y)) mp[y]=++m;
            x=mp[x]; y=mp[y];
            g[x].pb(y);
            g[y].pb(x);
        }
        clr(visit,0); id=0; clr(dfn,0); clr(cut,0);
        FOR1(i,m) if(!visit[i]) DFS(i,-1);
        printf("Case %d: ",++num);
        deal();
    }
}