Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)
	g := make([][]int, n+1)
	for i := 0; i < n; i++ {
		var u,k int
		fmt.Scan(&u)
		fmt.Scan(&k)
		g[u] = make([]int, k)
		for j := 0; j < k; j++ {
			fmt.Scan(&g[u][j])
		}
	}

	d := make([]int, n+1)
	f := make([]int, n+1)
	t := 1
	for i := 1; i <= n; i++ {
		t = dfs(&g, &d, &f, i, t)
	}

	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, d[i], f[i])
	}
}

func dfs(g *[][]int, d *[]int, f *[]int, id int, t int) int {
	if (*d)[id] > 0 {
		return t
	}
	(*d)[id] = t
	t += 1
	for i := 0; i < len((*g)[id]); i++ {
		t = dfs(g, d, f, (*g)[id][i], t)
	}
	(*f)[id] = t
	return t+1
}

C++: #include <iostream>
#include <string>
#include <vector>
#define WHITE 0
#define GRAY 1
#define BLACK 2
using namespace std;
int t = 0;

void visit(int u, int *color, int *d, int *f, vector<vector<int>> Adj){
    int zero = 0;
    color[u] = GRAY;
    d[u] = ++t;
    for (int i = 1; i <= Adj[u].size(); i++){
        if (Adj[u][i] == 0){
            break;
        }
        if (color[Adj[u][i]] == WHITE){
            visit(Adj[u][i], color, d, f, Adj);
        }
    }
    color[u] = BLACK;
    f[u] = ++t;
}

int main(int argc, char* argv[]) {
    int n, u, k, v;
    cin >> n;
    n++;
    int color[n], d[n], f[n];
    vector<vector<int>> Adj(n, vector<int>(n, 0));

    for (int i = 1; i <= n; i++) color[i] = WHITE;

    for (int i = 1; i < n; i++){
        cin >> u >> k;
        for (int j = 1; j <= k; j++){
            cin >> v;
            Adj[i][j] = v;
        }
    }

    for (int i = 1; i < n; i++)
        if (color[i] == WHITE)
            visit(i, color, d, f, Adj);

    for (int i = 1; i < n; i++){
        printf("%d %d %d\n", i, d[i], f[i]);
    }
    return 0;
}

C++: #include<iostream>
#include<string>
#include<cstdio>
#include<algorithm>
using namespace std;

int timex = 0;

int n;

string *color = new string[n];

int *d = new int[n];

int *f = new int[n];

int c[100][100];

void dfs(int u){
  color[u] = "glay";
  d[u] = ++timex;

  for(int v = 0; v < n; v++){
    if(c[u][v] == 1 && color[v] == "white"){
      dfs(v);
    }
  }

color[u] = "black";
f[u] = ++timex;

}

int main(){

  int n;

  cin >> n;

  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      c[i][j] = 0;
    }
  }

  for(int i = 0; i < n; i++){
    int x;
    cin >> x;
    int k;
    cin >> k;
    for(int j = 0; j < k; j++){
      int v;
      cin >> v;
      c[i][v - 1] = 1;
    }
  }

  for(int i = 0; i < n; i++){
    color[i] = "white";
  }

  dfs(0);

  for(int i = 0; i < n; i++){
    cout << i + 1 << ' ' << d[i] << ' ' << f[i] << endl;
  }




  return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int t;
int N;
int d[110], f[110];
vector<vector<int> > adj(110);
void dfs(int cur){
    d[cur] = t;
    t += 1;
    //cerr << "visiting " << cur << " " << t << endl;
    for(int i = 0; i < adj[cur].size(); ++i){
        int dst = adj[cur][i];
        if(d[dst] == 0){
            dfs(dst);
        }
    }
    f[cur] = t;
    t++;
}

int main(){
    cin >> N;
    t = 1;
    int u, k;
    for(int i = 0; i < N; ++i){
        d[i] = 0;
        f[i] = 0;
    }
    for(int i = 0; i < N; ++i){
        cin >> u >> k;
        for(int j = 0; j < k; j++){
            int v;
            cin >> v;
            adj[u].push_back(v);
        }
        sort(adj[u].begin(), adj[u].end());
    }
    for(int i = 1; i < N+1; ++i){
        if(d[i] == 0) dfs(i);
    }
    
    for(int i = 1; i < N+1; ++i){
        cout << 1 << " " << d[i] << " " << f[i] << endl;
    }
}

C++: #include <iostream>
using namespace std;

int a[100][100];
int n,p,q,r;
int T[100],F[100];
int Time = 0;
void dfs(int cur) {
	T[cur] = Time;
	Time += 1;
	for (int dst=0; dst < n; ++dst) {
		if(a[cur][dst] == 1 && T[dst] == -1) {
			dfs(dst);
		}
	}
	F[cur] = Time;
	Time += 1;
}

int main() {
	cin >> n;
	for (int i=0; i<n; ++i) {
		cin >> p >> q;
		T[i] = -1;
		for (int j=0; j<q; ++j) {
			cin >> r;
			a[p-1][r-1] = 1;
		}
	}
	dfs(0);
	for (int i=0; i<n-1; ++i) {
		cout << i+1 << " " << T[i]+1 << " " << F[i]+1 << endl;
	}
	cout << n << " " << T[n-1]+1 << " " << F[n-1]+1 << endl;
}

C++: #include <iostream>
#include <vector>
using namespace std;
vector<int> E[101];
bool visited[101];
int in[101];
int out[101];
int count=0;
int nv(int n)
{
	int i=1;
	for(i=1;i<=n;i++)
	{
		if ( visited[i]==false )
			return i;
	}
	if (i>n) return 0;
}

void bfs(int n)
{
	visited[n]=true;
	in[n]=++count;
	for(vector<int>::iterator it=E[n].begin();it!=E[n].end();++it)
	{
		int now=*it;
		if(visited[now]==false)
			bfs(now);
	}
	out[n]=++count;
}

int main()
{
	int n;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		int e,n0;
		cin>>e>>n0;
		for(int j=0;j<n0;j++)
		{
			int t;
			cin>>t;
			E[e].push_back(t);
		}
		visited[i]=false;
		in[i]=out[i]=0;
	}

	int now=nv(n);
	while(now!=0)
	{
		bfs(now);
		now=nv(n);
	}


/*	for(int i=1;i<=n;i++)
	{
		for(vector<int>::iterator it=E[i].begin();it!=E[i].end();++it)
			cout<<*it<<" ";
		cout<<endl;
	}
*/
	for(int i=1;i<=n;i++)
		cout<<i<<" "<<in[i]<<" "<<out[i]<<endl;
	return 0;

	

}

C++: #include <iostream>
using namespace std;

int n, t;
int v[100][100];
int d[100], f[100], r[100];

void stamp(int id) {
	if (d[id - 1] == 0) {
		d[id - 1] = t;
		t++;
		int i = 0;
		while (v[id - 1][i] == 0)
			i++;
		if (i < n && d[i] == 0)
			stamp(i + 1);
		else
			stamp(id);
	}
	else if (f[id - 1] == 0) {
		int i;
		for(i = 0; i < n; i++)
			if (v[id - 1][i] == 1 && d[i] == 0)
				stamp(i + 1);
		if (i > n - 1 && f[id - 1] == 0) {
			f[id - 1] = t;
			t++;
			int j1, ct = 0;
			for (int j = n - 1; j > -1; j--)
				if (v[j][id - 1] == 1 && f[j] == 0 && d[j] != 0) {
					j1 = j;
					ct++;
				}
			if (ct == 1)
				stamp(j1 + 1);
			else {
				for (int j = 1; j < n; j++)
					if (d[j] == d[id - 1] - 1)
						stamp(j + 1);
			}

			int k = 0;
			while (d[k] != 0)
				k++;
			if (k < n)
				stamp(k + 1);
		}
	}
	else	
		return;
}

int main()
{
	cin >> n;

	for (int i = 0; i < n; i++) {
		d[i] = 0;
		f[i] = 0;
	}

	for (int i = 0; i < n; i++)
		for (int j = 0; j < n; j++)
			v[i][j] = 0;

	for (int i = 0; i < n; i++) {
		int u, k, s;

		cin >> u >> k;

		for (int j = 0; j < k; j++) {
			cin >> s;
			v[u - 1][s - 1] = 1;
		}
	}

	t = 1;
	stamp(1);

	for (int i = 0; i < n; i++)
		cout << i + 1 << " " << d[i] << " " << f[i] << endl;

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

const int MAX=200;

int state[MAX],d[MAX],f[MAX],N;
vector<int> T[MAX];
stack<int> S;

void DFS(){
    int time=0,count=0;
    while(count!=N){
        for(int j=0;j<N;j++){
            if(state[j]==0){
                S.push(j);
                state[j]=1;
                time++;
                d[j]=time;
                break;
            }
        }
    while(S.size()){
        int a=S.top();
        bool flag=true;
        for(int i=0;i<T[a].size();i++){
            if(state[T[a][i]]==0){
                S.push(T[a][i]);
                state[T[a][i]]=1;
                time++;
                d[T[a][i]]=time;
                flag=false;
                break;
            }
        }
            if(flag){
                time++;
                state[a]=2;
                count++;
                f[a]=time;
                S.pop();
            }
            
        }
    }
    for(int i=0;i<N;i++){
        cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
    }
}

int main(){
   
    int u,k,a;cin>>N;
    
    for(int i=0;i<N;i++){
        state[i]=0;
        d[i]=0;
        f[i]=0;
    }
    
    for(int i=0;i<N;i++){
        cin>>u>>k;
        u--;
        for(int j=0;j<k;j++){
            cin>>a;
            a--;
            T[u].push_back(a);
        }
    }
    DFS();
}