Mining Your Own Business UVALive - 5135（点双联通分量）

these days I‘m tired！，but very happy。。。

#include<cstdio>
#include<cstring>
#include<stack>
#include<vector>
#include<algorithm>
using namespace std;

typedef long long lld;

const int MAXN = <<;

struct Edge
{
    int u,v;
};

vector <int> G[MAXN],bcc[MAXN];
stack <Edge> S;
int pre[MAXN],is_cut[MAXN],bccno[MAXN];
int bcc_cnt,dfs_clock;

int dfs(int u,int fa)
{
    int low_u = pre[u] = ++dfs_clock;
    int child = ;
    for(int i = ;i < G[u].size();i++)
    {
        int v = G[u][i];
        Edge e = (Edge){u,v};
        if(!pre[v])
        {
            child++;
            S.push(e);
            int low_v = dfs(v,u);
            low_u = min(low_u,low_v);
            if(low_v >= pre[u])
            {
                is_cut[u] = ;
                bcc_cnt++;
                bcc[bcc_cnt].clear();
                for(;;)
                {
                    Edge x = S.top();
                    S.pop();
                    if(bccno[x.u] != bcc_cnt)
                    {
                        bcc[bcc_cnt].push_back(x.u);
                        bccno[x.u] = bcc_cnt;
                    }
                    if(bccno[x.v] != bcc_cnt)
                    {
                        bcc[bcc_cnt].push_back(x.v);
                        bccno[x.v] = bcc_cnt;
                    }
                    if(x.u == u && x.v == v)
                        break;
                }
            }
        }
        else if(pre[v] < pre[u] && v != fa)
        {
            S.push(e);
            low_u = min(low_u,pre[v]);
        }
    }
    if(child ==  && fa == -) is_cut[u] = ;
    return low_u;
}

void find_bcc(int n)
{
    memset(pre,,sizeof(pre));
    memset(is_cut,,sizeof(is_cut));
    memset(bccno,,sizeof(bccno));
    dfs_clock = bcc_cnt = ;
    for(int i = ;i < n;i++)
        if(!pre[i]) dfs(i,-);
}

int main()
{
    int cas = ;
    int n;
    while(~scanf("%d",&n) && n)
    {
        for(int i = ;i < *n;i++)
            G[i].clear();
        int max_id = ;
        for(int i = ;i < n;i++)
        {
            int a,b;
            scanf("%d%d",&a,&b);
            max_id = max(max_id,a);
            max_id = max(max_id,b);
            a--;b--;
            G[a].push_back(b);
            G[b].push_back(a);
        }

        find_bcc(max_id);
        //printf("bcc_cnt = %d\n",bcc_cnt);

        int ans_num = ;
        lld ans_count = ;
        if(bcc_cnt == )
        {
            ans_num = ;
            ans_count = (lld)bcc[].size()*(bcc[].size()-)/;
        }
        else
        {
            for(int i = ;i <= bcc_cnt;i++)
            {
                int cc = ;
                for(int j = ;j < bcc[i].size();j++)
                    if(is_cut[bcc[i][j]] == )
                        cc++;
                if(cc == )
                {
                    ans_num++;
                    ans_count *= bcc[i].size()-;
                }
            }
        }
        printf("Case %d: %d %lld\n",++cas,ans_num,ans_count);
    }
    return ;
}