Go: package main

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

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Scan()
	num, _ := strconv.Atoi(sc.Text())
	nodes := make(map[int]*node)

	for i := 0; i < num; i++ {
		sc.Scan()
		id, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		nodeNum, _ := strconv.Atoi(sc.Text())
		n := node{id, make([]int, 0), 0, 0}
		for j := 0; j < nodeNum; j++ {
			sc.Scan()
			nid, _ := strconv.Atoi(sc.Text())
			n.nexts = append(n.nexts, nid)
		}
		nodes[id] = &n
	}

	s := Stack{}
	for i := 1; i < len(nodes)+1; i++ {
		if nodes[i].s != 0 {
			continue
		}
		walk(i, &nodes, s)
	}
	for i := 1; i < len(nodes)+1; i++ {
		fmt.Printf("%v %v %v\n", (*nodes[i]).id, (*nodes[i]).s, (*nodes[i]).e)
	}
}

var time int

func walk(nid int, nodes *map[int]*node, s Stack) {
	n := (*nodes)[nid]
	if n.s != 0 {
		return
	}
	time++
	n.s = time
	s.Push(n)
	for _, v := range n.nexts {
		walk(v, nodes, s)
	}
	time++
	n.e = time
}

type node struct {
	id    int
	nexts []int
	s     int
	e     int
}

// Stack is Stack
type Stack struct {
	stack []interface{}
}

// Push new value
func (stack *Stack) Push(val interface{}) {
	stack.stack = append(stack.stack, val)
}

// Pop new value
func (stack *Stack) Pop() interface{} {
	val := stack.stack[len(stack.stack)-1]
	stack.stack = stack.stack[0 : len(stack.stack)-1]
	return val
}

C++: #include<iostream>
#include<stack>
using namespace std;
static const int N=100;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;

int n,M[N][N];
int color[N],d[N],f[N],tt;
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)//未訪問なら訪問
            {
                color[v]=GRAY;
                d[v]=++tt;
                S.push(v);
            }
        }
        else
        {
            S.pop();//もどる
            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()
{
    int u,k,v;
    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;
}

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

using namespace std;

int G[100][100];
int In[100];
int Out[100];
void init() {
	for (int i = 0; i < 100; i++) {
		for(int j = 0; j < 100; j++)
			G[i][j] = 0;
		In[i] = -1;
		Out[i] = -1;
	}	
}

void dfs(int src);

int main() {
	init();
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			int v_j;
			cin >> v_j;
			G[u - 1][v_j - 1] = 1;
		}
	}
	dfs(0);
	for (int i = 0; i < n; i++)
		cout << i + 1 << " " << In[i] << " " << Out[i] << endl;
}

int t = 1;

void dfs(int cur) {
	In[cur] = t;
	t++;
	for (int dst = 0; dst < 100; dst++)
		if (G[cur][dst] == 1 && In[dst] == -1)
			dfs(dst);
	Out[cur] = t;
	t++;
}

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

#define N 100
// 未訪問
#define WHITE 0
// 訪問中
#define GRAY 1
// 訪問済み
#define BLACK 2

int n,M[N][N];
int color[N];
// 訪問時間
int d[N];
// 探索終了時間
int f[N];
// 時間
int t = 0;
// 探索済みの頂点を一から探索しないように、nt[u]にすでに探索済みの番号を入れ、次回は探索した移行の頂点から探索されるようにする
int nt[N];

/**
    uに隣接するvを番号順に取得する
*/
int next(int u){
    // 探索済み移行の頂点から探索を始める
    for(int v = nt[u];v < n;++v){
        nt[u] = v + 1;
        if(M[u][v]){
            return v;
        }
    }
    return -1;
}

/**
    スタックを用いた深さ優先探索
*/
void dfs(int u){
    for(int i = 0;i < n;++i){
        nt[i] = 0;
    }
    
    stack<int> S;
    S.push(u);
    color[u] = GRAY;    // 訪問中
    d[u] = ++t;      // 訪問時間
    
    while(!S.empty()){
        int topU = S.top();
        // 隣接する頂点
        int v = next(topU);
        // 隣接する頂点が見つかった場合
        if(v != -1){
            // 未探索のケース
            if(color[v] == WHITE){
                color[v] = GRAY;
                // 訪問時間
                d[v] = ++t;
                S.push(v);
            }
        }else{
            // 未訪問の頂点が見つからなかった
            S.pop();
            // 探索終了
            color[topU] = BLACK;
            // 探索終了時間
            f[topU] = ++t;
        }
    }
}

int main(){
    int u,k,v;
    cin >> n;
    
    // 初期化
    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){
        cin >> u >> k;
        // 頂点を移動する
        u--;
        // 頂点の数だけ回す
        for(int j = 0;j < k;++j){
            cin >> v;
            --v;    // ずらす
            M[u][v] = 1;
        }
    }
    for(int i = 0;i < n;++i){
        if(color[i] == WHITE){
            dfs(i);
        }
    }
    
    for(int i = 0;i < n;++i){
        cout << i + 1 << " " << d[i] << " " << f[i] << endl;
    }
    
    return 0;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <functional>
#include <algorithm>
#include <array>
#include <stack>
#include <map>

using namespace std;

template<typename ISTREAM>
void readGraphListAsMatrix(const size_t n, ISTREAM& cin, vector< vector<int> >& graphMatrix) {
	graphMatrix = vector< vector<int> >(n, vector<int>(n, 0));
	for (size_t i = 0; i != n; ++i) {
		size_t u;
		size_t k;
		cin >> u;
		cin>> k;
		for (size_t j = 0; j != k; ++j) {
			size_t v;
			cin >> v;
			graphMatrix.at(u - 1).at(v - 1) = 1;
		}
	}
}

void printMatrix(const vector< vector<int> >& grapthMatrix) {
	const size_t n = grapthMatrix.size();
	for (size_t i = 0; i != n; ++i) {
		const vector<int>& adj = grapthMatrix.at(i);
		cout << adj.front();
		for (size_t j = 1; j != n; ++j) {
			cout << " " << adj.at(j);
		}
		cout << endl;
	}
}


template<typename T>
void execute(T& cin) {
	size_t n;
	cin >> n;
	vector< vector<int> > graphMatrix;
	readGraphListAsMatrix(n, cin, graphMatrix);
	stack<int> visitedNodeIDs;
	int time = 0;
	vector<pair<int, int>> timeStamp(n,make_pair(0,0));//pair<初回訪問時刻, 完了時刻>
	vector<vector<int>::iterator> searchBeginPos; {
		searchBeginPos.reserve(n);
		for (auto& v : graphMatrix)searchBeginPos.push_back(v.begin());
	}

	vector<pair<int, int>>::iterator visitTimeSearchPos = timeStamp.begin();
	while (
		(visitTimeSearchPos = find_if(visitTimeSearchPos, timeStamp.end(), [&](const pair<int, int>& df) {return df.first == 0; }))
		!= timeStamp.end()) {
		visitedNodeIDs.push(distance(timeStamp.begin(), visitTimeSearchPos));
		visitTimeSearchPos->first = ++time;
		++visitTimeSearchPos;
		while (!visitedNodeIDs.empty()) {
			const int nodeID_1 = visitedNodeIDs.top();
			vector<int>& neighbourNodeList = graphMatrix.at(nodeID_1);
			vector<int>::iterator result = find(searchBeginPos.at(nodeID_1), neighbourNodeList.end(), 1);
			if (result != neighbourNodeList.end()) {
				const int nextVisitID_1 = distance(neighbourNodeList.begin(), result);
				timeStamp.at(nextVisitID_1).first = time + 1;
				for (auto&v : graphMatrix) v.at(nextVisitID_1) = 0;
				visitedNodeIDs.push(nextVisitID_1);
				searchBeginPos.at(nodeID_1) = result + 1;
			}
			else {
				//隣接リストに検索対象なし
				timeStamp.at(nodeID_1).second = time + 1;
				visitedNodeIDs.pop();
			}
			++time;
		}
	}
	for (int i = 0; i != n; ++i) {
		cout << i + 1 << " " << timeStamp.at(i).first << " " << timeStamp.at(i).second << endl;
	}
}

int main()
{

	execute(cin);

	return 0;
}