Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	f         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes] = &DirectedGraphNode{}
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].f = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

var time = 0

func fillDistancesByDepthFirstSearch(g *DirectedGraph) {
	for _, u := range g.nodes[1:] {
		if !u.visited {
			dfsVisit(g, u)
		}
	}
}

func dfsVisit(g *DirectedGraph, u *DirectedGraphNode) {
	time++
	u.d = time

	u.visited = true
	for _, v := range u.adjacents {
		if !v.visited {
			v.parent = u
			dfsVisit(g, v)
		}
	}
	time++
	u.f = time
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	fillDistancesByDepthFirstSearch(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		fmt.Println(node.key, node.d, node.f)
	}
}

C++: #include<cstdio>
#define MAX_N 100
#define WHITE 0
#define GRAY 1
#define BLACK 2

int n, u, k, v;
int adj[MAX_N][MAX_N];
int color[MAX_N], d[MAX_N], f[MAX_N], tt;

void dfs_visit(int num){
	color[num] = GRAY;
	d[num] = ++tt;
	for(int i = 0; i < n; i++){
		if(adj[num][i] == 0) continue;
		if(color[i] == WHITE){
			dfs_visit(i);
		}
	}
	color[num] = BLACK;
	f[num] = ++tt;
}

void dfs(){
	for(int i = 0; i < n; i++){
		color[i] = WHITE;
	}
	tt = 0;

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

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

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

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

	dfs();

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

	return 0;
}

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

using namespace std;

//4
//1 1 2
//2 1 4
//3 0
//4 1 3

//1 1 8
//2 2 7
//3 4 5
//4 3 6

const int MAX = 100;

int n;

int t = 0;

int G[MAX + 1][MAX + 1];
int d[MAX + 1];
int f[MAX + 1];

int color[MAX + 1];
int WHITE = 0;
int GRAY = 1;
int BLACK = 2;

void dfs(int v) {
	color[v] = GRAY;
	d[v] = ++t;

	for (int i = 1; i <= n; ++i) {
		if (G[v][i] == 1 && color[i] == WHITE)
			dfs(i);
	}

	color[v] = BLACK;
	f[v] = ++t;
}

int main() {

	scanf("%d", &n);

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

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

	for (int i = 1; i <= n; ++i) {
		if (color[i] == WHITE)
			dfs(i);
	}

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

	return 0;

}

C++: #include <iostream>
#include <iomanip>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <algorithm>
#include <cstdio>
#include <utility>
#include <string>
#include <cmath>
#include <cstdlib>
#include <cstring>

using namespace std;

typedef uint64_t u64;
typedef int64_t s64;
typedef uint32_t u32;
typedef int32_t s32;
typedef vector<s32> vs32;
typedef vector<u32> vu32;
typedef vector<s64> vs64;
typedef vector<u64> vu64;

const double PI=3.14159265358979323846;

#define MAX(x, y) ((x) < (y) ? (y) : (x))
#define MIN(x, y) ((x) > (y) ? (y) : (x))

#define rep(i, N) for(int i = 0; i < N; ++i)

#define CEIL(x, y) (((x) + (y) - 1) / (y))
#define MOD 1000000007ULL

class DirectedGraph
{
public:
    DirectedGraph()
    : t(1)
    {}
    DirectedGraph(int n)
    : t(1), g(vector< vs32 >(n)), d(vs32(n, 0)), f(vs32(n, 0))
    {}
    ~DirectedGraph() {}

    void dfs(int i)
    {
        d[i] = t++;
        rep (j, g[i].size())
        {
            if (d[g[i][j]] == 0)
            {
                dfs(g[i][j]);
            }
        }
        f[i] = t++;
    }

    int t;
    vector< vs32 > g;
    vs32 d;
    vs32 f;
};

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    DirectedGraph dg(n);
    int u, v;
    int c;
    rep (i, n)
    {
        cin >> u >> c;
        --u;
        dg.g[u].resize(c);
        rep (j, c)
        {
            cin >> v;
            --v;
            dg.g[u][j] = v;
        }
    }

    rep (i, n)
    {
        if (dg.d[i] == 0)
        {
            dg.dfs(i);
        }
    }

    rep (i, n)
    {
        cout << i + 1 << " " << dg.d[i] << " " << dg.f[i] << "\n";
    }
    return 0;
}

C++: 
#include<iostream>

using namespace std;

const int MAX = 100;

void search(bool graph[MAX][MAX], int find[], int done[], int n, int u,int& count) {
	count++;
	find[u] = count;
	for (int i = 0; i < n; i++) {
		if (graph[u][i] && find[i] == 0) {
			search(graph, find, done, n, i, count);
		}
	}
	count++;
	done[u] = count;
}

int main() {
	bool check[MAX] = { false };
	int find[MAX] = { 0 };
	int done[MAX] = { 0 };
	bool graph[MAX][MAX] = { {false} };
	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 temp;
			cin >> temp;
			graph[u - 1][temp - 1] = true;
		}
	}

	int count = 0;
	for (int i = 0; i < N; i++) {
		if (find[i] == 0) {
			search(graph, find, done, N, i, count);
		}
	}

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

	return 0;
}