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>

using namespace std;

const int N = 100;
const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;

int n = 0;
int color[N];
int M[N][N];
int 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;//初始化

    for(u=0;u<n;u++)
    {
        if(color[u]==WHITE)
            dfs_visit(u);
    }
    for(u=0;u<n;u++)
        cout << u+1 << " " << d[u] << " " << f[u] << "\n";
}

int main()
{
    int u,k,v,i,j;
    cin >> n;

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

    for(i=0;i<n;i++)
    {
        cin >> u >> k;
        u--;
        for(j=0;j<k;j++)
        {
            cin >> v;
            v--;
            M[u][v] = 1;
        }
    }

    dfs();

    return 0;
}

C++: #include <cstdio>
#include <vector>
#include <algorithm>
#include <stack>

using namespace std;

using Weight=int;
using DArray=vector<Weight>;
using DMatrix=vector<DArray>;

static const Weight INF=1<<29;

struct Edge {
    size_t src, dst;
    Weight weight;
    Edge() {}
    Edge(size_t src, size_t dst, Weight weight=1):
        src(src), dst(dst), weight(weight)
    {}
};

bool operator<(const Edge &e, const Edge &f) {
    if (e.weight != f.weight) {
        return e.weight > f.weight;
    } else {
        return e.src!=f.src? e.src<f.src : e.dst<f.dst;
    }
}

using Edges=vector<Edge>;
using Vertex=vector<Edge>;
using Graph=vector<Vertex>;

void join(Graph &g, size_t s, size_t d, Weight w=1) {
    // non-directed
    g[s].push_back(Edge(s, d, w));
    g[d].push_back(Edge(d, s, w));
}

void connect(Graph &g, size_t s, size_t d, Weight w=1) {
    // directed
    g[s].push_back(Edge(s, d, w));
}

void dfs(const Graph &g, size_t v, int &t, vector<int> &d, vector<int> &f) {
    d[v] = t;
    for (const Edge &e: g[v])
        if (!d[e.dst])
            dfs(g, e.dst, ++t, d, f);

    f[v] = ++t;
}

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

    Graph g(n);
    for (size_t i=0; i<n; ++i) {
        size_t k;
        scanf("%*d %zu", &k);
        for (size_t j=0; j<k; ++j) {
            size_t v;
            scanf("%zu", &v);
            --v;

            connect(g, i, v);
        }
    }

    vector<int> d(n), f(n);
    int t=1;
    dfs(g, 0, t, d, f);

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

    return 0;
}

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

int n,M[N][N];
int color[N];
//??\??¶????????°??¶???
int d[N];
//??\??¶???????????¶???
int f[N];
//??¶???
int tt;

//??¨???????????°?????°?????±?????????????´¢
void dfs_visit(int u){
    int v;
    //??£??¨???????????°
    color[u]=GRAY;
    //??¶????????°
    d[u]=++tt;
    for(v=0;v<n;v++)
        if(M[u][v]&&color[v]==WHITE)
            dfs_visit(v);
    //????????????
    color[u]=BLACK;
    f[u]=++tt;
}

void dfs(){
    //????§????
    for(int u=0;u<n;u++)
        color[u]=WHITE;
    tt=0;

    for(int u=0;u<n;u++)
        //??\????????????u?????????????????±?????????????´¢
        if(color[u]==WHITE)
            dfs_visit(u);
    for(int u=0;u<n;u++)
        printf("%d %d %d\n",u+1,d[u],f[u]);
}

int main(){
    int u,v,k;

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

    dfs();
}

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

int m[101][101];
int visit[101];
int d[101];
int f[101];
int n, t;

void dfs(int u){
  visit[u] = 1;
  d[u] = t;
  t++;
  
  for(int i = 0; i < n; ++i){
    if(m[u][i] == 1 && visit[i] == 0){
      dfs(i);
    }
  }

  f[u] = t;
  t++;
}

main()
{
  int u, k, v;
  t = 1;

  cin >> n;
  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; 
    //隣接行列
    }
  }

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

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

  return (0);
}

C++: #include <vector>
#include <iostream>
using namespace std;
int n, u, k, v, t, d[100][2]; vector<int> g[100];
void rec(int pos) {
	for(int i = 0; i < g[pos].size(); i++) {
		if(!d[g[pos][i]][0]) {
			d[g[pos][i]][0] = ++t;
			rec(g[pos][i]);
			d[g[pos][i]][1] = ++t;
		}
	}
}
int main() {
	cin >> n;
	for(int i = 0; i < n; i++) {
		cin >> u >> k;
		for(int j = 0; j < k; j++) cin >> v, g[u - 1].push_back(v - 1);
	}
	for(int i = 0; i < n; i++) cout << i + 1 << ' ' << d[i][0] << ' ' << d[i][1] << endl;
}

C++: /*
AizuOJ ALDS1_11_B

???;DFS;????´¢;?¨????
*/
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

const int MAXN=110;
int n;
vector<int> adj[MAXN];
int visited[MAXN], d[MAXN], f[MAXN], t=0;

void dfs(int s) {
    visited[s]=true;
    d[s]=++t;
    for (vector<int>::iterator iter=adj[s].begin(); iter!=adj[s].end(); iter++) {
        if (!visited[*iter]) dfs(*iter);
    }
    f[s]=++t; // ????????¶????????????
}

void add_edge(int u, int v) {
    adj[u].push_back(v);
}

int k, tmp, v;
int main() {
    scanf("%d", &n);
    for (int u=1; u<=n; u++) {
        scanf("%d%d", &tmp, &k); // k ?????????
        while (k--) {
            scanf("%d", &v);
            add_edge(u, v);
        }
        sort(adj[u].begin(), adj[u].end());
    }
    for (int u=1; u<=n; u++) {
        if (!visited[u]) dfs(u);
    }
    for (int u=1; u<=n; u++) {
        printf("%d %d %d\n", u, d[u], f[u]);
    }
    return 0;
}