Go: #include <bits/stdc++.h>
using namespace std;
static const int WHITE = 0;
static const int GRAY  = 1;
static const int BLACK = 2;
static const int N     = 100;

int n, tt;
vector<vector<int>> M(N, vector<int>(N));
vector<int> color(N), d(N), f(N);

void dfs_visit(int u) {
  color[u] = GRAY;
  d[u]     = ++tt;
  for (int v = 0; v < n; v++) {
    if (M[u][v] == 0) continue;
    if (color[v] == WHITE) { dfs_visit(v); }
  }
  color[u] = BLACK;
  f[u]     = ++tt;
}

void dfs() {
  tt = 0;

  for (int u = 0; u < n; u++) {
    if (color[u] == WHITE) dfs_visit(u);
  }
  for (int u = 0; u < n; u++) {
    printf("%d %d %d\n", u + 1, d[u], f[u]);
  }
}

int main() {
  int u, v, k;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> u >> k;
    u--;
    for (int j = 0; j < k; j++) {
      cin >> v;
      v--;
      M[u][v] = 1;
    }
  }

  dfs();
}

C++: #include <bits/stdc++.h>
#define REP(i,n) for (int i=0;i<(n);i++)
#define All(v) (v).begin(),(v).end()
#define mp(a,b) make_pair(a,b)
#define pb(a) push_back(a)
using namespace std;
typedef long long llint;
typedef pair<int, int> P;
const int MOD = (int)1e9 + 7;
const int INF = 999999999;

int N;
int tt = 0;
vector< vector<int> > G;
vector<int> H, d, f;
int itrNum[100001];
stack<int> S;

void dfs(int u){
    S.push(u);
    H[u] = 0;

    while(!S.empty()){
        u = S.top();  // ?¨????????????????
        if(d[u] == 0) d[u] = ++tt;
        auto itr_v = next(G[u].begin(), itrNum[u]);
        itrNum[u]++;
        if(itr_v != G[u].end()){
            int v = *itr_v;
            if(H[v] == -1){
                H[v] = 0;
                S.push(v);
            }
        }else{
            S.pop();
            H[u] = 1;
            f[u] = ++tt;
        }
    }
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> N;
    G = vector<vector<int> >(N);
    H = vector<int>(N, -1);
    d = vector<int>(N, 0);
    f = vector<int>(N, 0);
    memset(itrNum, 0, sizeof(itrNum));
    REP(i, N){
        int u,k;
        cin >> u >> k;
        u--;
        REP(j ,k){
            int v;
            cin >> v;
            v--;
            G[u].pb(v);
        }
    }

    REP(i, N) if(H[i] == -1) dfs(0);
    REP(i, N){
        cout << i+1 << " " << d[i] << " " << f[i] << "\n";
    }
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MOD 1000000007
#define INF 1e9
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define all(x) (x).begin(),(x).end()

int a[101][101],f[101],e[101],t=1;
int color[101];
int n;

void dfs(int u){
    f[u]=t++;
    color[u]=1;
    rep(v,n){
        if(color[v]==0 && a[u][v]) dfs(v);
    }
    e[u]=t++;

}

int main() {
    cin>>n;
    rep(i,n){
        int u,cur;
        cin>>u>>cur;
        rep(j,cur){
            int v;
            cin>>v;
            a[u-1][v-1]=1;
        }
    }
    rep(i,n){
        if(!color[i]) dfs(i);
    }
    rep(i,n) cout<<i+1<<" "<<f[i]<<" "<<e[i]<<endl;
}

C++: #include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<vector>
#include<queue>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
using namespace std;

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef stack<int> SI;
typedef pair<int,int> PII;
typedef long long LL;

#define d(x)  cout<<#x<<" = "<<(x)<<endl;
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define REACH(i,c) for(typeof((c).rbegin()) i=(c).rbegin(); i!=(c).rend(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c,n) sort(c,c+n)
#define VSORT(c) sort((c).begin(),(c).end())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define DFOR(i,b,a) for(int i=(b)-1;i>=(a);--i)
#define DREP(i,n) DFOR(i,n,0)
#define INF 2000000000

const double EPS = 1e-10;
const double PI  = acos(-1.0);
////////////////////////////////////////////////
//?????????????????????????????????
SI s;//?¨?????????????????????????
int n;//??????????????°
int t;//??????
int d[101];//??????????????????????¨????????????????????????????????????????
int f[101];//??????????????£??\?????????????????????????????????????????????????????????
int a[101][101];//??£??\?????????
int p[101];//??£??\?????????????¨???????????????????????????????
int flag;//???
int main()
{
	cin>>n;
	FOR(i,1,n+1)//??£??\??????????????????
	{
		int k,m;cin>>k>>m;
		a[k][0]=m;
		FOR(j,1,m+1)
		{
			int x;cin>>x;
			a[k][j]=x;
		}
	}
	d[1]=1;
	FOR(i,1,101)p[i]=1;//??£??\??????????????????????????????????????????1???????????????
	for(s.push(1),t=2;;t++)
	{
		//s.top()?????????????????????????????????
		if(a[s.top()][0]==0)
		{
			f[s.top()]=t;
			s.pop();
		}
		else
		{
			int next=a[s.top()][p[s.top()]];//next????¬?????¨?????????????????????????
			for(;d[next]!=0;)//???????????????????¨??????????????????¢???
			{
				p[s.top()]++;//????????????????????????????¬??????????????????????
				if(p[s.top()]>a[s.top()][0])//?????????????????£????????????????????????????¨??????????????????°
				{
					f[s.top()]=t;
					s.pop();//?¬?????¨????????????????????????????
					flag=1;//???????????????
					break;//????????????????????????
				}
				next=a[s.top()][p[s.top()]];//?¨????????????????????????´??°
			}
			if(flag==0)//?????????????????£???????????????????¨??????????????????°
			{
				s.push(next);//?¬?????¨??????????for???????????§??????????????????
				d[s.top()]=t;//???????????????????????????????????????????¨????????????????????????????????????????
			}
		}
		flag=0;//???????????????
		if(f[1]!=0)break;//??¢?´¢??????
	}
	FOR(i,1,n+1)cout<<i<<" "<<d[i]<<" "<<f[i]<<endl;
	return 0;
}

C++: #include <iostream>
#include <stack>
using namespace std;
static const int N=100;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;
 
//???¶?????????°
int n;
//?????\??????
int M[N][N];
//???°??????¶????????¢????
int color[N];
//??\???¶?????????°???¶???
int d[N];
//??\???¶????????????¶???
int f[N];
//???¶???
int tt;
 
int nt[N];
 
//????????????????????????u?????????v
int next(int u){
    for(int v=nt[u];v<n;v++){
        nt[u]=v+1;
        if(M[u][v]&&color[v]==WHITE)
            return v;
    }
    return -1;
}
 
//???¨?????????°??????±??????????????´?¢
void dfs_visit(int r){
    for(int i=0;i<n;i++)
        nt[i]=0;
 
    stack<int> S;
    S.push(r);
    color[r]=GRAY;
    //??????°???¶???
    d[r]=++tt;
 
    while(!S.empty()){
        int u=S.top();
        int v=next(u);
        if(v!=-1&&color[v]==WHITE){
            color[v]=GRAY;
            d[v]=++tt;
            S.push(v);
        }
        else{
            //????????????
            S.pop();
            color[u]=BLACK;
            f[u]=++tt;
        }
    }
}
 
void dfs(){
    //?????§????
    for(int i=0;i<n;i++)
        color[i]=WHITE;
    tt=0;
 
    //??\????????????u??????????????????±??????????????´?¢
    for(int u=0;u<n;u++)
        if(color[u]==WHITE)
            dfs_visit(u);
 
    for(int i=0;i<n;i++)
        cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
}
 
int main(){
    int u,k,v;
 
    cin>>n;
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            M[i][j]=0;
 
    for(int i=0;i<n;i++){
        cin>>u>>k;u--;
        for(int j=0;j<k;j++){
            cin>>v;v--;
            M[u][v]=1;
        }
    }
 
    dfs();
}