Go: package main

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

type TimeRecord struct {
	discoverTime int
	finishTime   int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	timeRecordMap := make([]TimeRecord, n)
	childrenMap := make([][]int, n)
	for i := 1; i <= n; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		timeRecordMap[node-1] = TimeRecord{-1, -1}

		childNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		childrenMap[node-1] = make([]int, childNum)
		for j := 0; j < childNum; j++ {
			child, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			childrenMap[node-1][j] = child
		}
	}

	// TODO: always start with 1?
	timer := 1
	visit(1, &timer, childrenMap, timeRecordMap)
	for k, v := range timeRecordMap {
		fmt.Printf("%d %d %d\n", k+1, v.discoverTime, v.finishTime)
	}
}

func visit(currentNode int, timer *int, childrenMap [][]int, timeRecordMap []TimeRecord) {
	if timeRecordMap[currentNode-1].discoverTime > 0 {
		return
	}
	children := childrenMap[currentNode-1]
	timeRecordMap[currentNode-1] = TimeRecord{*timer, timeRecordMap[currentNode-1].finishTime}
	(*timer)++
	for i := 0; i < len(children); i++ {
		visit(children[i], timer, childrenMap, timeRecordMap)
	}
	timeRecordMap[currentNode-1] = TimeRecord{timeRecordMap[currentNode-1].discoverTime, *timer}
	(*timer)++
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include<stdio.h>
#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 2

int tt;
int d[N];
int f[N];
int M[N][N];
int color[N];
int 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;
        else if(color[v]== WHITE){
            dfs_visit(v);
        }
    }
    color[u] = BLACK;

    f[u] = ++tt;
}



int main(){
    int u;
    int v;
    int k;



    scanf("%d",&n);

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


    for(int i=0; i<n; i++){
        scanf("%d",&u);
        scanf("%d",&k);
        for(int j=0; j<k; j++){
            scanf("%d",&v);

            M[u-1][--v] = 1;
        }
        
    }

    tt = 0;

    for(int i=0; i<n;i++) {
        if(color[i] == WHITE) dfs_visit(i);
    }

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

    return 0;

}

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

int G[110][110];
bool seen[110];
int d[110];
int f[110];
int N;
int t = 1;

void dfs( int s ){
    seen[s] = 1;
    d[s] = t++;
    for( int i = 0; i < N; i++ ){
        if( G[s][i] && !seen[i] ){
            dfs( i );
        }
    }
    f[s] = t++;
}

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

    for( int i = 0; i < N; i++ ){
        if( !seen[i] ){
            dfs( i );
        }
    }

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

C++: #include<iostream>
using namespace std;
#define MAX 100

int mat[MAX][MAX] = {};
int n;
int time = 0;
int d[MAX] = {}, f[MAX] = {};
bool c[MAX];

void dfs_visit(int u){
    c[u] = true;
    d[u] = ++time;
    for(int i = 0; i < n; i++){
        if(mat[u][i] == 0)  continue;
        if(!c[i])   dfs_visit(i);
    }
    f[u] = ++time;
}

void dfs(){
    for(int i = 0; i < n; i++){
        if(!c[i])   dfs_visit(i);
    }

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

int main(){
    cin >> n;
    
    for(int i = 0; i < n; i++){
        int x, k, y;
        cin >> x >> k;
        while(k-- > 0){
            cin >> y;
            mat[x-1][y-1] = 1;
        }
    }

    dfs();
    return 0;
}

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

const int MAX_N = 100;
int to[MAX_N][MAX_N];
int ans[MAX_N][2];
int depth = 1;

void dfs(int x) {
  if (ans[x][0] == -1) ans[x][0] = depth++;
  for (int i=0; to[x][i] != -1; i++) {
    dfs(to[x][i]);
  }
  if (ans[x][1] == -1) ans[x][1] = depth++;
}

int main() {
  int N;
  cin >> N;
  for (int i=0; i<N; i++) {
    for (int j=0; j<N; j++) {
      to[i][j] = -1;
    }
    ans[i][0] = ans[i][1] = -1;
  }
  for (int i=0; i<N; i++) {
    int tmp, n;
    cin >> tmp >> n;
    for (int j=0; j<n; j++) {
      int t;
      cin >> t; t--;
      to[i][j] = t;
    }
  }

  dfs(0);
  for (int i=0; i<N; i++) {
    cout << i+1 << " " << ans[i][0] << " " << ans[i][1] << endl;
  }
  return 0;
}

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

int G[105][105]={};
int d[105]={},f[105]={};
int N,T=0;

void Gprint(int n){
    cout<<"\\|";
    for(int i=0; i<n; i++)cout<<i+1;
    cout<<endl;
    for(int i=0; i<n+2; i++)cout<<"-";
    cout<<endl;
    for(int i=0; i<n; i++){
        cout<<i+1<<"|";
        for(int j=0; j<n; j++){
            cout<<G[i][j];
        }
        cout<<endl;
    }
}

void dfs(int n){
    if(d[n])return;
    d[n]=++T;
    for(int i=0; i<N; i++){
        if(G[n][i])dfs(i);
    }
    f[n]=++T;
}

int main(){
    int u,k,v;

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

//    Gprint(N);

    dfs(0);

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

C++: #include<stdio.h>

int d[100],f[100],n,g[100][100],time=1;

int func(int n){
    d[n]=time++;
    int i,j;
    for(i=0;i<n;i++){
        if(gn][i]==1 && d[i]==0){
            func(i);
        }
    }
    f[n]=time++;
}

int main(void){
    int i, j, u, k, v;
    scanf("%d",&n);
    for(i=0;i<n;i++){
        scanf("%d %d",&u,&k);
        for(j=0;j<k;j++){
            scanf("%d",&v);
            g[u-1][v-1]=1;
        }
    }
    func(0);
    for(i=0;i<n;i++){
        if(d[i]==0){
            func(i);
        }
    }
    for(i=0;i<n;i++){
        printf("%d %d %d\n",i+1,d[i],f[i]);
    }
    return 0;
}

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

static const int N = 100;
static const int WHITE = 0; //訪問した
static const int GRAY = 1; //訪問中
static const int BLACK = 2; //全て訪問済み

int n, M[N][N]; //頂点の個数、辺のリスト
int color[N], d[N], f[N], tt; //色、発見時刻、完了時刻、時間
int nt[N];

int next(int u) {
	for (int v = nt[u]; v < n; v++) {
		nt[u] = v + 1;
		if (M[u][v]) 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) {
			if (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;
		nt[i] = 0;
	}
	tt = 0;
	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(void) {
	int u, k, v; //頂点番号、出次数、隣接リスト
	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();
	return 0;
}