Go: package main

/*
深さ優先探索
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		ints := eGetInts(scanner)
		num, vcount := ints[0], ints[1]
		g[i] = make([]int, vcount)
		for j := 0; j < vcount; j++ {
			g[num][j] = ints[j+2]
		}
	}
	hist := make([]struct{ d, f int }, n+1)
	t := 0
	var visit func(int)
	visit = func(num int) {
		if hist[num].d == 0 {
			stack := []int{}
			t++
			hist[num].d = t
			stack = append(stack, num)
			for len(stack) > 0 {
				// トップを訪問する
				top := stack[len(stack)-1]
				for i := 0; i < len(g[top]); i++ {
					if hist[g[top][i]].d == 0 {
						t++
						hist[g[top][i]].d = t
						stack = append(stack, g[top][i])
						goto endloop
					}
				}
				// 訪問場所がなくなったら
				// pop
				stack = stack[0 : len(stack)-1]
				t++
				hist[top].f = t
			endloop:
			}
		}
	}
	for i := 1; i < n+1; i++ {
		visit(i)
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, hist[i].d, hist[i].f)
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

C++: #include <stdio.h>

#define N 101

int color[N];
int n, G[N][N],f[N],d[N],time;

void visit(int);

int main(){
  int i,j,v,vnext,k;
 
  scanf("%d",&n);

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

  for(i=0; i<n; i++){
    scanf("%d %d",&v,&k);
    for(j=0; j<k; j++){
      scanf("%d",&vnext);
      G[v-1][vnext-1] = 1; 
    }
  }

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

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

void visit(int u){

  int i; 
  color[u]=1;
  d[u]= ++time;
  for(i=0; i<n; i++){
    if(G[u][i] == 1){
      if(color[i] == 0)visit(i);
    }
  }

  color[u]= 2;
  f[u]=++time;
}

C++: #include<stdio.h>
 
#define MAX 101
#define WHITE -1
#define GRAY 0
#define BLACK 1
 
int n,t;
int color[MAX],d[MAX],f[MAX],Adj[MAX][MAX];
 
dfs(){
  int i;
 
  for(i=0;i<n;i++) color[i]=WHITE;
  t=0;
  for(i=0;i<n;i++){
    if(color[i]==WHITE) visit(i);
  }
}
 
visit(int r){
  int i;
 
  color[r]=GRAY;
  d[r]=++t;
 
  for(i=0;i<n;i++){
    if(Adj[r][i]==1 && color[i]==WHITE) visit(i);
  }
 
  color[r]=BLACK;
  f[r]=++t;
}
 
int main(){
  int i,u,k,j,v;
 
  for(i=0;i<MAX;i++){
    for(j=0;j<MAX;j++){ 
      Adj[i][j]=0;
    }
  }
 
  scanf("%d",&n);
  for(i=0;i<n;i++){
    scanf("%d%d",&u,&k);
    for(j=0;j<k;j++){
      scanf("%d",&v);
      Adj[u-1][v-1]=1;
    }
  }
 
  dfs();
 
  for(i=0;i<n;i++){
    printf("%d %d %d\n",i+1,d[i],f[i]);
  }
 
  return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;
#define EXIST 1
#define TODO 1
#define DONE 0
int graph[200][200];
int used[200];
int disc[200];
int fin[200];
int n;
int elapsed;

void dfs(int pos) {
  disc[pos] = ++elapsed;
  used[pos] = DONE;
  for (int i = 0; i < n; i++) {
    if (graph[pos][i] == EXIST && used[i] == TODO) {
      dfs(i);
    }
  }
  fin[pos] = ++elapsed;
}

int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    int u, k, v; cin >> u >> k;
    for (int j = 0; j < k; j++) {
      cin >> v;
      graph[u-1][v-1] = EXIST;
    }
    used[i] = TODO;
  }
  for (int i = 0; i < n; i++) {
    if (used[i] == TODO) {
      dfs(i);
    }
  }
  for (int i = 0; i < n; i++) {
    cout << i+1 << " " << disc[i] << " " << fin[i] << endl; 
  }
}

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

int n,M[N][N];
int color[N],d[N],f[N],tt;

void dfs_visit(int u){
    int v;
    color[u]=GRAY;
    d[u]=++tt;

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

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

    for(i=0; i<n; i++){
        scanf("%d %d",&u,&k);
        for(j=0; j<k; j++){
            scanf("%d",&v);
            v--;
            M[u][v]=1;
        }
    }

    dfs();
    return 0;
}

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

using namespace std;

int** gmtrx;
int* d, *f;
int t, n;

class Stack{
public:
	Stack(int num):head(0){
		s = new int [num];
		for(int i=0; i<num; ++i){
			s[i] = 0;
		}
	}
	~Stack(){ delete[] s; }
	void push_back(int vtx){
		s[head++] = vtx;
	}
	int pop_back(){
		--head;
		int tmp = s[head];
		s[head] = 0;
		return tmp;
	}
	int back(){
		if(head<=0) return -1;
		return s[head-1];
	}
private:
	int head;
	int* s;
};


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

	gmtrx = new int*[n];
	d = new int [n]; //discovery
	f = new int [n]; //finish
	Stack st(n);

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

	for(int i=0; i<n; ++i){
		int v, num, a;
		scanf("%d %d",&v,&num);
		--v;
		for(int j=0; j<num; ++j){
			scanf("%d",&a);
			--a;
			gmtrx[v][a] = 1;
		}
	}

	for(int i=0; i<n; ++i){
		int vtmp=i;
		if( d[vtmp]!= 0) continue;
		st.push_back(vtmp);
		vtmp=0;
		while(st.back()!=-1){
			if(d[st.back()]==0){
				++t;
				d[st.back()] = t;
			}
			else if(f[st.back()]!=0){
				vtmp = st.pop_back();
				++vtmp;
				continue;
			}
			for(int j=vtmp; j<=n; ++j){
				if(j==n){
					++t;
					f[st.back()] = t;
					vtmp = st.pop_back();
					++vtmp;
					break;
				}
				if(gmtrx[st.back()][j]){
					if(d[j]==0) st.push_back(j);
					else continue;
					break;
				}
			}
		}
	}

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

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

	return 0;
}