Go: package main

import "fmt"

type node struct {
	id, d, v int
	adj      []node
}

var n int
var seen []bool
var graph []node

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

func dfs(v, t int) int {
	// fmt.Printf("dfs(v %d, t %d) en:\n", v, t)
	seen[v] = true
	graph[v].v = t
	tt := t
	for _, vv := range graph[v].adj {
		if !seen[vv.id] {
			tt = max(tt, dfs(vv.id, tt+1))
		}
	}
	graph[v].d = tt + 1
	// fmt.Printf("dfs(v %d, t %d) ex: d %d\n", v, t, graph[v].d)
	return graph[v].d
}

func main() {
	fmt.Scan(&n)
	graph = make([]node, n+1)
	for i := 1; i <= n; i++ {
		var u, k, v int
		fmt.Scan(&u, &k)
		graph[u].id = u
		// 頂点uはk個の隣接頂点を持っている
		for j := 0; j < k; j++ {
			fmt.Scan(&v)
			var t node
			t.id = v
			graph[u].adj = append(graph[u].adj, t)
		}
	}
	// fmt.Println("n", n, "graph", graph)
	seen = make([]bool, n+1)
	// t := dfs(1, 1)
	v, t := 1, 1
	done := false
	for !done {
		tt := dfs(v, t)
		done = true
		for i := range seen {
			if !seen[i] {
				done = false
				v = graph[i].id
				t = tt
				break
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, graph[i].v, graph[i].d)
	}
}

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

bool V[100];
int S[100];
int E[100];
vector<int> G[100];

void calc(int n, vector<int>* G, int& cnt) {
  V[n] = true;
  S[n] = cnt++;
  for (auto it = G[n].begin(); it != G[n].end(); ++it) {
    if (!V[(*it)]) {
      calc((*it), G, cnt);
    }
  }
  E[n] = cnt++; 
}

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

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

  int cnt = 0;
  for (int i = 0; i < n; ++i) {
    if (V[i]) continue;
    calc(i, G, cnt);
  }

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

  return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;
vector<vector<int>> adjlist;
int time=1;
vector<int> d;
vector<int> f;
void input(int n){
	vector<int> f={0,0};
	adjlist.push_back(f);
  for(int i=0;i<n;i++){
    vector<int> list;
    int ln;
    cin>>ln;
    list.push_back(ln);
    cin>>ln;
    list.push_back(ln);
    for(int j=0;j<ln;j++){
      int an;
      cin>>an;
      list.push_back(an);
    }
    adjlist.push_back(list);
  }
}

void depth_search(int id){
	vector<int> list=adjlist[id];
	for(int j=0;j<list[1];j++){
		if(d[list[2+j]]<0){
			d[list[2+j]]=++time;
			depth_search(list[2+j]);
		}
	}
	f[id]=++time;
}
 
void print(int n){
  for(int i=1;i<n+1;i++){
    cout<<i<<' '<<d[i]<<' '<<f[i]<<endl;
  }
}
int main(){
  int n;
  cin>>n;
	d=vector<int> (n+1,-1);
	f=vector<int> (n+1,-1);
	d[1]=1;
	f[1]=1;
  input(n);
  depth_search(1);
  print(n);
  return 0;
}

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) {
				color[V] = GRAY;
				D[V] = ++TT;
				S.push(V);
			}
		}
		else {
			S.pop();
			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<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 ) {
        color[v] = GRAY;
        d[v] = ++tt;
        S.push(v);
      }
    } else {
      S.pop();
      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;
}