Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strconv"
)

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve(parseProblem())
}

type graph struct {
	size  int
	edges [][]int
}

func parseProblem() *graph {
	n := scanInt(sc)
	g := &graph{
		size:  n,
		edges: make([][]int, n),
	}
	for i := 0; i < g.size; i++ {
		_ = scanInt(sc)
		k := scanInt(sc)
		g.edges[i] = make([]int, k)
		for j := 0; j < k; j++ {
			g.edges[i][j] = scanInt(sc) - 1
		}
	}
	return g
}

func resolve(g *graph) {
	ds := make([]int, g.size)
	fs := make([]int, g.size)
	time := 0
	for i := 0; i < len(ds); i++ {
		if ds[i] == 0 {
			time++
			time = _dfs(ds, fs, time, g, i)
		}
	}
	for i := 0; i < len(ds); i++ {
		fmt.Println(i+1, ds[i], fs[i])
	}
	return
}

func _dfs(ds, fs []int, time int, g *graph, idx int) int {
	ds[idx] = time
	for _, next := range g.edges[idx] {
		if ds[next] > 0 {
			continue
		}
		time++
		time = _dfs(ds, fs, time, g, next)
	}
	time++
	fs[idx] = time
	return time
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

C++: #include <stdio.h>
#include <iostream>
#include <stack>
#include <string>
using namespace std;

#define NUM 100
int node_num;
int V[NUM + 1][NUM + 1];
int d[NUM + 1];
int f[NUM + 1];
string color[NUM + 1];
int t;
int pos;
stack<int> s;

void createAdj(int n){
    for(int j = 0; j <= n; j++){
        if(j == 0){
            V[0][j] = 0;
        }
        V[0][j] = 1;
    }

    for(int i = 1; i < NUM; i++){
        for(int j = 1; j < NUM; j++){
            V[i][j] = 0;
        }
    }

    for(int i = 0; i < n; i++){
        int num1;
        scanf("%d", &num1);

        int n;
        scanf("%d", &n);

        int num2;
        for(int j = 0; j < n; j++){
            scanf("%d", &num2);
            V[num1][num2] = 1;
        }
    }
}

int search(int n){
    for(int i = 1; i <= node_num; i++) {
        if(V[n][i] == 1 && color[i] == "white")
            return i;
    }
    return -1;
}

void dfs_init(){
    t = 0;
    for(int i = 0; i < NUM; i++){
        color[i] = "white";
    }
}

void dfs(){
    s.push(0);
    pos = 0;
    color[0] = "grey";
    d[0] = t;

    while(s.size()){
        int u = s.top();
        int next_node = search(u);
        if(next_node != -1){
            pos = next_node;
            s.push(next_node);
            pos = next_node;
            t++;
            color[next_node] = "grey";
            d[next_node] = t;
        }else{
            s.pop();
            color[u] = "black";
            t++;
            f[u] = t;
        }
    }
}

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

int main(void){
    scanf("%d", &node_num);
    createAdj(node_num);

    dfs_init();
    dfs();

    print();
}

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

bool A[110][110];
int flag[110],in[110],out[110];
int now=1,n;

void dfs(int u){
	flag[u]=1;
	in[u]=now++;
	for(int i=1;i<=n;i++){
		if(flag[i]==0 && A[i][u]==true){
			dfs(i);
		}
	}
	out[u]=now++;
	return ;
}

int main(){
	int a,b,c;
	cin>>n;
	for(int i=1;i<=n;i++){
			for(int j=1;j<=n;j++){
				A[i][j]=false;
		}
	}
	for(int i=1;i<=n;i++){
		cin>>a>>b;
		for(int j=1;j<=b;j++){
			cin>>c;
			A[a][c]=true;
			A[c][a]=true;
		}
	}
	for(int i=1;i<=n;i++){
		if(flag[i]==0) dfs(i);
	}
	for(int i=1;i<=n;i++){
		cout<<i<<" "<<in[i]<<" "<<out[i]<<endl;
	}
	return 0;
}

C++: #include<iostream>
#include<stdio.h>

using namespace std;
int d[101];
int f[101];
int n;
int M[101][101];
int t;
void DFS(int v) {
	t = t + 1;
	d[v] = t;
	for (int j = 1; j < n + 1; j++) {
		if (M[v][j] == 1) {
			if (d[j] == 0) {
				DFS(j);

			}
		}
	}
	t = t + 1;
	f[v] = t;

}

int main() {
	int  u, k, v;//頂点数、頂点の番号、出次数、隣接する頂点の番号
	t = 0;

	cin >> n;



	//初期化
	for (int i = 0; i < 101; i++) {
		d[i] = 0;
		f[i] = 0;
		for (int j = 0; j < 101; j++) {
			M[i][j] = 0;

		}
	}

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


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

	return 0;
}

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

using namespace std;
static const int MAX=101;
bool Visited[MAX]; //??\?????????????¢??????????
vector<int> Adjacency[MAX];
int dTime[MAX]; int fTime[MAX]; //?¢??????°??¶??´????¢?????????¶??´
void dfs(int i,int& clock) //??¶????????°?????\???????????¨
{
    clock++;
    Visited[i]=true;
    dTime[i]=clock; //???????????°??¶??´
    for(int j=0;j<Adjacency[i].size();j++)
    {
        if(Visited[Adjacency[i][j]]==true) continue;
        dfs(Adjacency[i][j],clock);
    }
    clock++; //???????????????????¢????
    fTime[i]=clock;
}

int main()
{
    int n;
    cin>>n;
    for(int i=1;i<=n;i++) Visited[i]=false;

    for(int i=1;i<=n;i++)
    {
        int p;cin>>p;
        int num;
        cin>>num;

        for(int j=0;j<num;j++)
        {
            int t;
            cin>>t;
            Adjacency[p].push_back(t);
        }
    }
    int clock=0;
    dfs(1,clock);
    for(int i=1;i<=n;i++)
        cout<<i<<' '<<dTime[i]<<' '<<fTime[i]<<endl;
}

C++: #include<iostream>

int d[101]={0};
int f[101]={0};
int us[101]={0};
int V[101][101]={0};
int t=1;
int n;

void tansaku(int x)
{
  d[x]=t++;
  us[x]++;
  for(int i=0;i<n;i++){
    if(V[x][i]==1 and us[i]==0){
      tansaku(i);
    }
  }
  f[x]=t++;
}


int main()
{
  int n;
  int u,k,v;
  std::cin>>n;
  for(int i=0;i<n;i++){
    std::cin>>u>>k;
    for(int j=0;j<k;j++){
      std::cin>>v;
      V[u-1][v-1]=1;
    }
  }
  for(int i=0;i<n;i++){
    if(us[i]==0){
      tansaku(i);
    }
  }
  for(int i=0;i<n;i++){
    std::cout<<i+1<<" "<<d[i]<<" "<<f[i]<<"\n";
  }
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define REP(i,n) for(int i=0; i<(n); i++)
#define REP2(i,x,n) for(int i=x; i<(n); i++)
#define PRINT(x) cout<<(x)<<endl
#define INF 1000000000000 // 10^12
#define MOD 1000000007 // 10^9+7
#define PB push_back
#define MP make_pair

const int MAX_N = 100, MAX_K = 100;

int n, u, k, v[MAX_K];

vector<int> G[MAX_N];
int d[MAX_N], f[MAX_N];
int t = 0;

void dfs(int);

int main() {
    // input
    cin >> n;
    REP(i, n) {
        cin >> u >> k;
        u--;
        REP(j, k) {
            cin >> v[j];
            v[j]--;
            G[u].PB(v[j]);
        }
    }

    // init d
    REP(i, n) d[i] = -1;

    // dfs
    REP(i, n) {
        if (d[i] == -1) dfs(i);
    }

    // output
    REP(i, n) {
        int id = i + 1;
        printf("%d %d %d\n", id, d[i], f[i]);
    }

    return 0;
}

void dfs(int pos) {
    d[pos] = ++t;
    REP(i, G[pos].size()) {
        int to = G[pos][i];
        if (d[to] != -1) continue;
        dfs(to);
    }
    f[pos] = ++t;
    return;
}