Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	n := len(list)
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list[0 : n-1] {
		buf.Write([]byte(fmt.Sprintf("%d ", v)))
	}
	buf.Write([]byte(fmt.Sprintf("%d\n", list[n-1])))
	buf.Flush()
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

//solve

const MAX = 100
const WHITE = 0
const GRAY = 1
const BLACK = 2

var time, n int

//隣接行列
var M [MAX][MAX]int

//d[i]: 最初にiを訪問した時刻。発見時刻
//f[i]: iの隣接リストを訪問し終えた時刻。完了時刻
var color, d, f [MAX]int

func dfs_visit(u int) {
	color[u] = GRAY
	time++
	d[u] = time
	//隣接を調べる
	for v := 0; v < n; v++ {
		if M[u][v] == 0 {
			continue
		}
		//隣接するvが、未訪問だった場合
		if color[v] == WHITE {
			dfs_visit(v)
		}
	}
	//訪問完了処理
	color[u] = BLACK
	time++
	f[u] = time
	//訪問完了
}

func dfs() {
	//初期化
	for u := 0; u < n; u++ {
		color[u] = WHITE
	}
	time = 0

	//未訪問のuを始点として、深さ優先探索
	for u := 0; u < n; u++ {

		if color[u] == WHITE {
			dfs_visit(u)
		}
	}

	for u := 0; u < n; u++ {
		fmt.Println(u+1, d[u], f[u])
	}
}

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 0; i < n; i++ {
		u, k := nextInt(), nextInt()
		M[u-1][u-1] = 0

		//fmt.Println(u, k)
		if k > 0 {
			for j := 0; j < k; j++ {

				v := nextInt()
				M[u-1][v-1] = 1

			}
		}

	}

	dfs()

}

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

typedef pair<int, int> edge;

int vernum[101];
edge path[101][101];
int n;

edge found[101];

int t=0;
void dfs(int v){
    t++;
    found[v].first = t;
    int i=0;
    while(1){
        if(!path[v][i].first)
            break;
        if(!found[path[v][i].second].first){
            dfs(path[v][i].second);
        }
        i++;
    }
    t++;
    found[v].second = t;
}

int main() {
    int i, j;
    ios_base::sync_with_stdio(0);
    
    int e, v;
    cin >> n;
    
    for(i=1; i<=n; i++){
        cin >> vernum[i];
        cin >> e;
        for(j=0; j<e; j++){
            cin >> v;
            path[i][j] = make_pair(i, v);
        }
    }
    
    for(i=1; i<=n; i++){
        if(!found[i].first)
            dfs(i);
    }
    
    for(i=1; i<=n; i++){
        cout << vernum[i] << " " << found[i].first << " " << found[i].second << endl;
    }
    
    
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

int g[105][105],b[105],f[105],cnt=1,n,is[105];

void dfs(int v)
{
    is[v]=1;
    b[v]=cnt++;
    for(int i=1;i<=n;i++){
        if(i==v) continue;
        if(g[v][i]&&!is[i]) dfs(i);
    }
    f[v]=cnt++;
}

int main()
{
    int v1,d,v2;
    cin>>n;
    memset(g,0,sizeof g);
    memset(is,0,sizeof is);
    for(int i=0;i<n;i++){
        cin>>v1>>d;
        for(int i=0;i<d;i++){
            cin>>v2;
            g[v1][v2]=1;
        }
    }
    dfs(1);
    for(int i=1;i<=n;i++){
        cout<<i<<" "<<b[i]<<" "<<f[i];
        if(i!=n) cout<<endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
#define ll long long
#define INF 999999999
#define MOD 1000000007

using namespace std;

typedef pair<int,int>P;

struct edge{
	int from;
	int to;
};

const int MAX_N = 100;

vector<edge> G[MAX_N];
bool flag[MAX_N];
P res[MAX_N];
int t = 1;

void dfs(int x)
{
	res[x].first = t++;
	flag[x] = true;
	for(int i=0;i<G[x].size();i++){
		edge e = G[x][i];
		if(!flag[e.to]){
			dfs(e.to);
		}
	}
	res[x].second = t++;
}

int main()
{
	int n;
	cin >> n;
	for(int i=0;i<n;i++){
		int id,m;
		cin >> id;
		cin >> m;
		for(int j=0;j<m;j++){
			edge e;
			int end;
			cin >> end;
			e.from = id-1;
			e.to = end-1;
			G[id-1].push_back(e);
		}
	}
	fill(flag,flag+n,false);
	int time=0;
	for(int i=0;i<n;i++){
		if(!flag[i]){
			dfs(i);
		}
	}		
	for(int i=0;i<n;i++){
		cout << i+1 << " " << res[i].first << " " << res[i].second << "\n";
	}
}

C++: #include <cstdio>
#include <utility>
#include <vector>
#define rep(i,a) for(int i=0;i<(a);++i)

int n;
std::vector<std::vector<int> > G;
std::vector<bool> used;
std::vector<std::pair<int, int> > res;
int tim = 1;

void dfs( int v )
{
  used[v] = true;
  res[v].first = tim++;

  for( int u : G[v] ) if( !used[u] )
    dfs( u );

  res[v].second = tim++;

  return;
}

int main()
{
  scanf( "%d", &n );
  G.resize( n );
  used.resize( n );
  res.resize( n );

  rep( i, n )
  {
    int u, k;
    scanf( "%d%d", &u, &k );

    rep( j, k )
    {
      int v;
      scanf( "%d", &v );
      G[i].push_back( v-1 );
    }
  }

  rep( i, n ) if( !used[i] )
    dfs( i );

  rep( i, n )
    printf( "%d %d %d\n", i+1, res[i].first, res[i].second );

  return 0;
}

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


using namespace std;

int timecount = 0;

void dfs(int cur, int u, bool* visited, int* timearray, int* timearray_end, unordered_map<int, vector<int> > mymap);

int main(){
  int u, i, id, k, j;
  cin >> u;
  unordered_map<int, vector<int> > mymap;

  for (i = 0; i < u; ++i){
    cin >> id >> k;
    vector<int> points;
    for (j = 0; j < k; ++j){
      int a;
      cin >> a;
      points.push_back(a);
    }
    mymap[id] = points;
  }
  
  bool visited[u+1];
  for (j = 1; j <= u; ++j){
    visited[j] = false;
  }
  visited[1] = true;

  int timearray[u+1];
  for (j = 1; j <= u; ++j){
    timearray[j] = 0;
  }
  int timearray_end[u+1];
  for (j = 1; j <= u; ++j){
    timearray_end[j] = 0;
  }

  dfs(1, u, visited, timearray, timearray_end, mymap);

  for (j = 1; j <= u; ++j){
    cout << j << " " << timearray[j] << " " << timearray_end[j]<< endl;
  }

}

void dfs(int cur, int u, bool* visited, int* timearray, int* timearray_end, unordered_map<int, vector<int> > mymap){
  timecount++;
  timearray[cur] = timecount;

  for(int i = 1; i <= u; ++i){
    
    if((i!=cur)&&(find(mymap[cur].begin(), mymap[cur].end(), i) != mymap[cur].end())&&(!visited[i])){
      visited[i] = true;
      dfs(i, u, visited, timearray, timearray_end, mymap);
    }
  }
  timecount++;

  timearray_end[cur] = timecount;
}

C++: #include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int INF = 1e9;

int d[105] = { -1 }, f[105] = { -1 };
int n = -1;
int mat[105][105] = { { 0 } };
int visited[105] = { 0 };

void dfs(int v, int& now)
{
  d[v] = now;
  visited[v] = 1;
  ++now;
  for (int u = 1; u <= n; ++u) {
    if (mat[v][u] && !visited[u]) {
      dfs(u, now);
    }
  }
  f[v] = now;
  ++now;
}

int main()
{
  fscanf(stdin, "%d", &n);
  for (int i = 0; i < n; ++i) {
    int u = -1, k = -1, v = -1;
    fscanf(stdin, "%d %d", &u, &k);
    for (int j = 0; j < k; ++j) {
      fscanf(stdin, "%d", &v);
      mat[u][v] = 1;
    }
  }
  int now = 1;
  dfs(1, now);
  for (int i = 0; i < n; ++i) {
    fprintf(stdout, "%d %d %d\n", i + 1, d[i + 1], f[i + 1]);
  }
  return 0;
}