(tarjan) poj 1904

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<cstdlib>
#include<cmath>
#include<queue>
#include<vector>
#include<set>
#include<stack>
using namespace std;
stack<int> s;
vector<int> e[4010];
int n,top,newflag;
int Dfs[4010],low[4010],use[4010],isstack[4010];
void tarjan(int u)
{
    Dfs[u]=low[u]=++top;
    isstack[u]=1;
    s.push(u);
    for(int i=0;i<e[u].size();i++)
    {
        int v=e[u][i];
        if(!Dfs[v])
        {
            tarjan(v);
            low[u]=min(low[u],low[v]);
        }
        else if(isstack[v])
            low[u]=min(low[u],Dfs[v]);
    }
    if(Dfs[u]==low[u])
    {
        newflag++;
        int x;
        do
        {
            x=s.top();
            s.pop();
            isstack[x]=0;
            use[x]=newflag;
        }while(x!=u);
    }
}
int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        int k,x;
        scanf("%d",&k);
        while(k--)
        {
            scanf("%d",&x);
            e[i].push_back(x+n);
        }
    }
    for(int i=1;i<=n;i++)
    {
        int x;
        scanf("%d",&x);
        e[x+n].push_back(i);
    }
    for(int i=1;i<=n;i++)
    {
        if(!Dfs[i])
            tarjan(i);
    }
    for(int i=1;i<=n;i++)
    {
        priority_queue<int ,vector<int> ,greater<int> > q;
        for(int j=0;j<e[i].size();j++)
        {
            int v=e[i][j];
            if(use[v]==use[i])
                q.push(v-n);
        }
        printf("%d",q.size());
        while(!q.empty())
        {
            printf(" %d",q.top());
            q.pop();
        }
        printf("\n");
    }
    return 0;
}