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
		}
	}

	timer := 1
	startNode := 1
	for {
		visit(startNode, &timer, childrenMap, timeRecordMap)
		startNode = findStartNode(childrenMap, timeRecordMap)
		if startNode < 0 {
			break
		}
	}
	for k, v := range timeRecordMap {
		fmt.Printf("%d %d %d\n", k+1, v.discoverTime, v.finishTime)
	}
}

func findStartNode(childrenMap [][]int, timeRecordMap []TimeRecord) int {
	x := -1
	for node, timeRecord := range timeRecordMap {
		if timeRecord.discoverTime < 0 {
			x = node + 1
			break
		}
	}
	return x
}

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<bits/stdc++.h>
using namespace std;
#define MOD 1000000007
static const int white = 0;
static const int gray = 1;
static const int black = 2;

int n,t = 0;
int color[100],d[100],f[100],M[100][100];
int nt[100];

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] = ++t;

  while(!S.empty()) {
    int u = S.top();
    int v = next(u);
    if(v != -1) {
      if(color[v] == white) {
        color[v] = gray;
        d[v] = ++t;
        S.push(v);
      }
    }else {
      color[u] = black;
      f[u] = ++t;
      S.pop();
    }
  }

}

void dfs() {
  for(int i = 0;i < n;i++) {
    if(color[i] == white) 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 < 100;i++) {
  for(int j = 0;j < 100;j++) {
    M[i][j] = 0;
  }
}

for(int i = 0;i < 100;i++) {
  color[i] = white;
  nt[i] = 0;
  d[i] = 0;
  f[i] = 0;
}

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

}

dfs();

}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <stack>
#include <vector>
#include <algorithm>
#include <cmath>
#include <climits>
#include <cstring>
#include <queue>
#include <string>

using namespace std;

const double PI = 3.14159265358979;

int G[101][101];
bool visited[101];
int timex[101][2];
int now_time = 1;
int n;

void dfs(int node) {

	if (!visited[node]) {
		visited[node] = 1;
		timex[node][0] = now_time++;
		for (int i = 0; i < n; i++)	{
			if (G[node][i] && visited[i] == 0) {
				dfs(i);
			}
		}
		timex[node][1] = now_time++;
	}
}

void dfs_stack(int node) {

	stack<int> st;
	st.push(node);
	visited[node] = 1;
	timex[node][0] = now_time++;
	while (!st.empty()) {
		int ver = st.top();

		bool flag = false;
		for (int i = 0; i < n; i++)	{
			if (G[ver][i] && visited[i] == 0) {
				visited[i] = 1;
				timex[i][0] = now_time++;
				st.push(i);
				flag = true;
				break;
			}
		}
		if (!flag) {
			timex[ver][1] = now_time++;
			st.pop();
		}
	}

}


int main() {
	
	cin >> n;

	for (int i = 0; i < n; i++)	{
		int id, degree;
		cin >> id >> degree;
		for (int j = 0; j < degree; j++) {
			int idx; cin >> idx;
			G[id - 1][idx - 1] = 1;
		}
	}

	for (int i = 0; i < n; i++) {
		if (!visited[i])
			dfs_stack(i);
	}
	

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


	return 0;
}

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

using namespace std;

class Node{
private:
 unsigned long nodeId;
 unsigned long timestampStart;
 unsigned long timestampFinish;
 vector<unsigned long> adjectNode;
public:
 Node()
       : timestampStart(0),
         timestampFinish(0){

  cin >> nodeId;
  unsigned long adjectNodeNum = 0;
  cin >> adjectNodeNum;

  adjectNode.assign(adjectNodeNum, 0);
 
  for(unsigned long adjectNode_i = 0; adjectNode_i < adjectNodeNum; ++adjectNode_i){
   cin >> adjectNode[adjectNode_i];
  }

 };

 bool isStampStart(){
  if(timestampStart == 0) return false;
  return true;
 };

 void stampStart(const unsigned long time){
  timestampStart = time;
 };

 void stampFinish(const unsigned long time){
  timestampFinish = time;
 };

 unsigned long getAdjectNodeNum(){
  return adjectNode.size();
 };

 unsigned long getAdjectNode(unsigned  long adjectNode_i){
  return adjectNode[adjectNode_i]-1;

 };

 void display(){
  cout << nodeId          << " ";
  cout << timestampStart  << " ";
  cout << timestampFinish << endl;
 };

protected:

};

class Graph{
private:
 vector<Node*> graph;

 void DepthFirstSearch(Node* node, unsigned long &time){
  ++time;
  node->stampStart(time);
  for(unsigned long adjectNode_i = 0, adjectNodeMax = node->getAdjectNodeNum(); adjectNode_i < adjectNodeMax; ++adjectNode_i){
   unsigned long nextNode = node->getAdjectNode(adjectNode_i);
   if(!graph[nextNode]->isStampStart()) DepthFirstSearch(graph[nextNode], time);

  }
  ++time;
  node->stampFinish(time);

 };
public:
 Graph(unsigned long nodeNum = 0)
       : graph(vector<Node*>(nodeNum, 0)){

   for(unsigned long node_i = 0; node_i < nodeNum; ++node_i){
    graph[node_i] = new Node();
   }

  };

 void DepthFirstSearch(){
  unsigned long time = 0;
  for(unsigned long node_i = 0, nodeMax = graph.size(); node_i < nodeMax; ++node_i){
   if(!graph[node_i]->isStampStart()) DepthFirstSearch(graph[node_i], time);
  }
  
 };

 void display(){
  for(unsigned long node_i = 0, numMax = graph.size(); node_i < numMax; ++node_i){
   graph[node_i]->display();
  }
 };
protected:

};


int main(){

 unsigned long nodeNum = 0; cin >> nodeNum;

 Graph graph(nodeNum);
 graph.DepthFirstSearch();
 graph.display();

 return 0;
};

C++: #include<cstdio>
#include<cstring>
#include<vector>
#include<queue>
#include<algorithm>
#include<cmath>
#include<climits>
#include<string>
#include<set>
#include<numeric>
#include<map>
#include<iostream>
using namespace std;
#define rep(i,n) for(int i = 0;i<((int)(n));i++)
#define reg(i,a,b) for(int i = ((int)(a));i<=((int)(b));i++)
#define irep(i,n) for(int i = ((int)(n)-1);i>=0;i--)
#define ireg(i,a,b) for(int i = ((int)(b));i>=((int)(a));i--)
typedef long long ll;
typedef pair<ll, ll> mp;


int visitTime = 1;
int d[101]={},f[101]={},n[101],v[101][101],id;


void dfs(int cur) { // cur????¨????
	d[cur] = visitTime;// cur????¨??????????????¨????
	visitTime += 1;
	rep(i,n[cur]){ // ??¨????????? v[cur][i] ????????????
		if(d[v[cur][i]]==0){ // v[cur][i] ???????¨??????????
			dfs(v[cur][i]);
		}
	}
	f[cur] = visitTime;// cur ????¨????????????????????¨????
	visitTime += 1;
	// ??¢??°??????????????§???????????? (?????¢??°)
}

int main(void){
	int N;
	cin>>N;
	rep(i,N){
		cin>>id;
		cin>>n[id];
		rep(j,n[id])cin>>v[id][j];
	}
	reg(i,1,N){
		if(d[i]==0){
			dfs(i);
		}
	}
	reg(i,1,N)cout<<i<<" "<<d[i]<<" "<<f[i]<<endl;
	return 0;
}