Go: package main

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

// repr state of visited node
// WHITE yet visit
// GEAY  visiting
// BLACK visited
const (
	WHITE int = iota
	GRAY
	BLACK
)

type dfsGraph struct {
	g      [][]int
	colors []int
	stime  []int // Start time of visiting node
	ftime  []int // Finish time of visiting node
}

var time int

func makeAdjList() [][]int {
	var n int
	fmt.Scanf("%d", &n)

	adj := make([][]int, n)
	for i := 0; i < n; i++ {
		adj[i] = make([]int, n)
	}

	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		sc.Scan()
		nodeInfo := strings.Split(sc.Text(), " ")
		outDegree, _ := strconv.Atoi(nodeInfo[1])

		if outDegree > 0 {
			for k := 0; k < outDegree; k++ {
				j, _ := strconv.Atoi(nodeInfo[k+2])
				j-- // convert 1 based to 0 based
				adj[i][j] = 1
			}
		}
	}

	return adj
}

func (dg dfsGraph) dfsVisit(u int) {
	// 頂点uを訪問中に設定
	dg.colors[u] = GRAY
	time++
	dg.stime[u] = time

	// uの隣接nodeを訪問
	for v := 0; v < len(dg.g); v++ {
		if dg.g[u][v] == 0 {
			continue // 辺がなければスキップ
		}

		// vが未訪問なら訪問
		if dg.colors[v] == WHITE {
			dg.dfsVisit(v)
		}
	}

	// 頂点uを訪問済みに設定
	dg.colors[u] = BLACK
	time++
	dg.ftime[u] = time
}

func (dg dfsGraph) dfs() {
	for i := 0; i < len(dg.g); i++ {
		if dg.colors[i] == WHITE {
			dg.dfsVisit(i)
		}
	}
}

func (dg dfsGraph) printDfsTime() {
	for i := 0; i < len(dg.g); i++ {
		fmt.Printf("%d %d %d\n", i+1, dg.stime[i], dg.ftime[i])
	}
}

func main() {
	adj := makeAdjList()
	colors := make([]int, len(adj))
	stime := make([]int, len(adj))
	ftime := make([]int, len(adj))
	graph := dfsGraph{adj, colors, stime, ftime}
	graph.dfs()
	graph.printDfsTime()
}

C++: #include <stdio.h>
#include <stdint.h>
#include <iostream>
#include <fstream>
#include <cassert>
#include <climits>

#include <vector>
#include <memory>
using namespace std;

#define DEBUG (0)
#define USE_UNIQUE_PTR (0)

#if DEBUG
#define DPRINTF(...) do { \
    printf("D(L%d) %s: ", __LINE__, __func__); \
    printf(__VA_ARGS__); \
  } while (false)
#else
#define DPRINTF(...)
#endif // DEBUG

int g_num = -1;
int g_time = 1;

class Vertex {
public:
  Vertex() :
    id_(-1),
    discover_time_(-1),
    finish_time_(-1),
    adjacentNum_(0),
    adjacentIds_(nullptr),
    isVisited_(false) { }

  ~Vertex() {
#if !USE_UNIQUE_PTR
    if (adjacentIds_)
      delete [] adjacentIds_;
#endif
  }

  void setAdjacency(const vector<int> &adjacentIds);

  inline void setId(int id) { id_ = id; }
  inline void setDiscoverTime(int time) { discover_time_ = time; }
  inline void setFinishTime(int time) { finish_time_ = time; }
  inline void setVisited(bool visited) { isVisited_ = visited; }

  inline int getId() { return id_; }
  inline int getDiscoverTime() { return discover_time_; }
  inline int getFinishTime() { return finish_time_; }
  inline bool getVisited() { return isVisited_; }
  inline int getAdjacentNum() { return adjacentNum_; }
  inline int getAdjacentId(int idx) {
    if (adjacentIds_ == nullptr || idx > adjacentNum_)
      return -1;
    return adjacentIds_[idx];
  }

  void printTime();
  void printAdj();

private:
  int id_;
  int discover_time_;
  int finish_time_;

  int adjacentNum_;
#if USE_UNIQUE_PTR
  unique_ptr<int[]> adjacentIds_;
#else
  int *adjacentIds_;
#endif // USE_UNIQUE_PTR

  bool isVisited_;
};


void Vertex::setAdjacency(const vector<int> &adjacentIds)
{
  if (adjacentIds_) assert(1);

  adjacentNum_ = adjacentIds.size();
#if USE_UNIQUE_PTR
  adjacentIds_ = unique_ptr<int[]>(new int[adjacentNum_]);
#else
  adjacentIds_ = new int[adjacentNum_];
#endif // USE_UNIQUE_PTR

  for (int i = 0; i < adjacentNum_; i++)
  {
    adjacentIds_[i] = adjacentIds[i];
  }

}

void Vertex::printTime()
{
  printf("%d %d %d\n", id_, discover_time_, finish_time_);
}

void Vertex::printAdj()
{
  DPRINTF("%d %d", id_, adjacentNum_);
  for (int i = 0; i < adjacentNum_; i++) {
    printf(" %d", adjacentIds_[i]);
  }
  cout << endl;
}


void dfs(Vertex vertices[], int idx)
{

  DPRINTF("time %d  idx %d\n", g_time, idx);

  assert(idx <= g_num);

  Vertex &vtx = vertices[idx];

  if (!vtx.getVisited())
  {
    vtx.setDiscoverTime(g_time);
    g_time++;
  }

  for (int i = 0; i < vtx.getAdjacentNum(); i++)
  {
    int id = vtx.getAdjacentId(i);
    dfs(vertices, id);
  }

  if (!vtx.getVisited())
  {
    vtx.setFinishTime(g_time);
    vtx.setVisited(true);
    g_time++;
  }

}


int main()
{
  //int n;

  //cin >> n; cin.ignore();
  cin >> g_num; cin.ignore();
  DPRINTF("Node num %d\n", g_num);

  Vertex vertices[g_num+1];

  for (int i = 1; i <= g_num; i++)
  {
    int id;
    int num;

    cin >> id >> num;
    vertices[i].setId(id);
    DPRINTF("node %d (num %d)\n", id, num);

    vector<int> adjs;

    for (int j = 0; j < num; j++)
    {
      int adj;
      cin >> adj;

      adjs.push_back(adj);
    }

    if (adjs.size())
      vertices[i].setAdjacency(adjs);

    cin.ignore();
  }

#if DEBUG
  for (int i = 1; i <= g_num; i++) vertices[i].printAdj();
#endif

  for (int i = 1; i <= g_num; i++)
    if (!vertices[i].getVisited())
      dfs(vertices, i);

  for (int i = 1; i <= g_num; i++) vertices[i].printTime();

  return 0;
}

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

int gra[101][101];
int used[101];
int tt[101][2];
int n, a, b, c;

int dfs(int time, int ind){
	used[1] = 1;
	tt[ind][0] = time;
	for(int i=1; i<=n; i++){
		if(used[i]!=1 && gra[ind][i]==1){
			used[i] = 1;
			time = dfs(time+1, i);
		}
	}
	tt[ind][1] = ++time;
	return time;
}

int main(){
	cin>>n;
	int t = 0;
 	for(int i=0; i<n; i++){
 		cin>>a>>b;
		for(int j=1; j<=b; j++){
  			cin>>c;
 			gra[a][c]=1;
 		}
 	}
 	for(int i=1; i<=n; i++){
 		if(used[i]==0)t = dfs(++t, i); 		
	}
 	for(int i=1; i<=n; i++){
 		cout<<i<<" "<<tt[i][0]<<" "<<tt[i][1]<<"\n";
	}
 
 return 0;
}

C++: #include<iostream>
#include<cstdio>
using namespace std;
int arisutoteresu[200][200] = {0};
int imap[200][200] = {0};
int n,u[200],k[200];
int GetIt[200]={0};
int FinIt[200]={0};
bool used[200];
int fincou=1;
int Gcounter;
int Fcounter;
int Find;
void dfs(int where){
  Find++;
  //cout << "where " << where << " " << Find << endl; 
 GetIt[where]=Find;
  //cout << "GetIt[" << where << "] = " << GetIt[where] << endl;

  if(k[where] != 0){ 
    for(int i=0;i<k[where];i++){
      if(!used[imap[where][i]]){
	Gcounter++;

	used[imap[where][i]] = true;
	dfs(imap[where][i]);
	Find++;
      }
    }
  }
    FinIt[where] = Find+1;
     
}
 
int main(){
  
  int ad;
   
  scanf("%d",&n);
  for(int i=0;i<n;i++){
    cin >> u[i];
    cin >> k[u[i]];
    for(int j=0;j<k[u[i]];j++){
      cin >> ad;
      imap[u[i]][j] = ad;
    }
  }
 
 
  for(int j=0;j<200;j++)used[j] = false;
  Gcounter=Fcounter=1;
 
  Find = 0;
  int Index=0;
  bool fin = true;
  fincou = 1;

  
    for(int i=0;i<n;i++){
      if(!used[u[i]]){//cout << "not used" << u[i] << endl;
	used[u[i]]=true;
	dfs(u[i]);
       
      }
    }
    
    //dfs(u[0]);   

   
  
  //cout << "counter - " << Find << ", F" << fincou << endl;
  for(int i=0;i<n;i++){
    cout << u[i] << " " << GetIt[u[i]]  << " " << FinIt[u[i]];
    cout << endl;
  }
 
  return 0;
}