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 <map>
#include <set>
#include <list>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <utility>
#include <iostream>
#include <algorithm>
#include <functional>
#include <unordered_map>
#include <unordered_set>

using namespace std;

#define ll long long
#define ull unsigned long long
#define INF (1 << 30)
#define LLINF (1LL << 62)
#define MOD7 1000000007
#define MOD9 1000000009
#define eps 1e-9
#define P pair<int, int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pul pair<ull, ull>
#define all(a) (a).begin(), (a).end()
#define FOR(i,a,b) for (int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);--i)
#define REP(i,n) for (int i=0;i<(n);++i)
#define RREP(i,n) for (int i=(n)-1;i>=0;--i)

void YES() { cout << "YES" << endl; }
void NO() { cout << "NO" << endl; }
void Yes() { cout << "Yes" << endl; }
void No() { cout << "No" << endl; }
void yes() { cout << "yes" << endl; }
void no() { cout << "no" << endl; }

template<class T>
class DirectedGraph {
public:
	class Edge {
	public:
		int to;
		T cost;

		Edge(int t, T c) : to(t), cost(c) {}

		bool operator<(const Edge& right) const {
			return cost == right.cost ? to < right.to : cost < right.cost;
		}
	};

	vector<vector<Edge>> G;
	int V;

	DirectedGraph(int n = 0) {
		resize(n);
	}

	void resize(int n) {
		V = n;
		G.resize(n);
	}

	void addEdge(int from, int to, T cost = 0) {
		int v = max(from, to);
		if (v >= V)
			resize(v + 1);
		G[from].push_back(Edge(to, cost));
	}


	int t = 1;
	vector<pii> stamp;
	vector<bool> visit;
	void dfs(int s) {
		visit.resize(V);
		stamp.resize(V);
		calcDfs(s);
	}

	void calcDfs(int s) {
		if (visit[s])
			return;

		stamp[s].first = t++;

		visit[s] = true;
		for (int i = 0; i < G[s].size(); ++i) {
			calcDfs(G[s][i].to);
		}

		stamp[s].second = t++;
	}

	vector<int> bfs() {

	}
};

int main() {
	DirectedGraph<int> g;
	int n, id, k, to;
	cin >> n;
	for (int i = 0; i < n; ++i) {
		cin >> id >> k;
		while (k--) {
			cin >> to;
			g.addEdge(id, to);
		}
	}

	for (int i = 1; i <= n; ++i)
		g.dfs(i);

	for (int i = 1; i <= n; ++i) {
		printf("%d %d %d\n", i, g.stamp[i].first, g.stamp[i].second);
	}

	return 0;
}

C++: #include<iostream>
#include<vector>
using namespace std;
int cnt=1;
void depth(vector< vector<int> > &vv,vector<int> &f,vector<int> &c,int num){
	
	f[num]=cnt;
	cnt++;
	
	for(int i=0; i<vv[num].size(); i++){
		if(vv[num][i]!=0 && f[i]==0){
			depth(vv,f,c,i);
		}
	}

	c[num]=cnt;
	cnt++;

}
int main(){
	int n;
	cin>>n;
	vector< vector<int> > v(n,vector<int> (n,0));
	vector<int> ft(n,0);
	vector<int> ct(n,0);
	int u[n];
	for(int i=0; i<n; i++){
		int k;
		cin>>u[i]>>k;
		for(int j=0; j<k; j++){
			int x;
			cin>>x;
			v[i][x-1]=1;
		}
	}
	for(int i=0; i<n; i++){
		if(ft[i]==0){
			depth(v,ft,ct,i);
		}
		cout<<u[i]<<" "<<ft[i]<<" "<<ct[i]<<endl;
	}
  return 0;
}

C++: #include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> PLL;
typedef vector<int> VI;
typedef vector<char> VC;
typedef vector<double> VD;
typedef vector<string> VS;
typedef vector<ll> VLL;
typedef vector<PLL> VP;
const static int INF = 1000000000;
const static int MOD = 1000000007;
const int dx[4]={1, 0, -1, 0};
const int dy[4]={0, 1, 0, -1};
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
#define rep(i,n) for (ll i=0; i<(ll)(n); i++)
#define repd(i,n) for (ll i=n-1; i>=0; i--)
#define rept(i,m,n) for(ll i=m; i<n; i++)
#define stl_rep(itr, x) for (auto itr = x.begin(); itr != x.end(); ++itr)
#define all(x) (x).begin(), (x).end()
#define F first
#define S second
#define PF push_front
#define PB push_back
#define SORT(V) sort((V).begin(), (V).end())
#define RVERSE(V) reverse((V).begin(), (V).end())
#define paired make_pair
#define PRINT(V) for(auto v : (V)) cout << v << " "
//charを整数に
int ctoi(char c) { if (c >= '0' && c <= '9') { return c - '0'; } return 0; }
// 累積和 for (int i = 0; i < N; ++i) s[i+1] = s[i] + a[i]; 
void cum_sum(int N,vector<double> a, vector<double> &s){ for(int i=0; i<N; i++){ s[i+1]=s[i]+a[i];}}
//ユークリッドの控除法
ll gcd(ll a,ll b){
    if(b == 0) return a;
    return gcd(b,a%b);
}
//最小公倍数
ll lcm(ll a,ll b){
    ll g = gcd(a,b);
    return a / g * b; // Be careful not to overflow
}
//素数判定
bool is_prime(long long n) {
    if (n <= 1) return false;
    for (long long p = 2; p * p <= n; ++p) {
        if (n % p == 0) return false;
    }
    return true;
}
int getdigit(ll num){
    unsigned digit=0;
    while(num!=0){
        num /= 10;
        digit++;
    }
    return digit;
}
//空白文字も入力 getline(cin, S);
//桁数指定 setprecision
vector<bool> seen;
vector<int> first_order;
vector<int> last_order;

void dfs(vector<vector<int>> &G, int v, int &ptr){
    first_order[v]=ptr++;
    seen[v]=true;
    for(auto nv:G[v]){
        if(seen[nv]) continue;
        dfs(G, nv, ptr);
    }
    last_order[v]=ptr++;
}

int main()
{
    int n;
    cin >> n;
    vector<vector<int>> G(n);
    rep(i,n){
        int a,b;
        cin >> a;
        cin >> b;
        a--;
        rep(i,b){
            int c;
            cin >> c; 
            c--;
            G[a].push_back(c);
        }
    }
    seen.assign(n, false);
    first_order.resize(n);
    last_order.resize(n);
    int ptr=1;
    rep(i,n){
        if(seen[i]==false){
            dfs(G, i, ptr);
        }
    }
    for(int i=0; i<n; i++){
       cout << i+1 << " " << first_order[i] << " " << last_order[i] << endl;
    }
}