Go: package main

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

// repr state of visited node
// WHITE yet visit
// GEAY  visiting
// BLACK visited
const (
	WHITE int = iota
	GRAY
	BLACK
)

type dfsGraph struct {
	g      [][]int
	colors []int
	stime  []int // Start time of visiting node
	ftime  []int // Finish time of visiting node
}

var time int

func makeAdjList() [][]int {
	var n int
	fmt.Scanf("%d", &n)

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

	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		sc.Scan()
		nodeInfo := strings.Split(sc.Text(), " ")
		outDegree, _ := strconv.Atoi(nodeInfo[1])

		if outDegree > 0 {
			for k := 0; k < outDegree; k++ {
				j, _ := strconv.Atoi(nodeInfo[k+2])
				j-- // convert 1 based to 0 based
				adj[i][j] = 1
			}
		}
	}

	return adj
}

func (dg dfsGraph) dfsVisit(u int) {
	// 頂点uを訪問中に設定
	dg.colors[u] = GRAY
	time++
	dg.stime[u] = time

	// uの隣接nodeを訪問
	for v := 0; v < len(dg.g); v++ {
		if dg.g[u][v] == 0 {
			continue // 辺がなければスキップ
		}

		// vが未訪問なら訪問
		if dg.colors[v] == WHITE {
			dg.dfsVisit(v)
		}
	}

	// 頂点uを訪問済みに設定
	dg.colors[u] = BLACK
	time++
	dg.ftime[u] = time
}

func (dg dfsGraph) dfs() {
	for i := 0; i < len(dg.g); i++ {
		if dg.colors[i] == WHITE {
			dg.dfsVisit(i)
		}
	}
}

func (dg dfsGraph) printDfsTime() {
	for i := 0; i < len(dg.g); i++ {
		fmt.Printf("%d %d %d\n", i+1, dg.stime[i], dg.ftime[i])
	}
}

func main() {
	adj := makeAdjList()
	colors := make([]int, len(adj))
	stime := make([]int, len(adj))
	ftime := make([]int, len(adj))
	graph := dfsGraph{adj, colors, stime, ftime}
	graph.dfs()
	graph.printDfsTime()
}

C++: #include <stdio.h>
#define  MAX 100
#define FIRST 0
#define MIDDLE 1
#define END 2

int n,M[MAX][MAX];
int point[MAX],d[MAX],f[MAX],t;

void dfs_visit(int u){
    int v;
    point[u]=MIDDLE;
    d[u]=++t;
    for(v=0;v<n;v++){
        if(M[u][v]==0)continue;
        if(point[v]==FIRST){
            dfs_visit(v);
        }
    }
    point[u]=END;
    f[u]=++t;
}
void dfs(){
    int u;

    for(u=0;u<n;u++)point[u]=FIRST;
    t=0;

    for(u=0;u<n;u++){
        if(point[u]==FIRST)dfs_visit(u);
    }
    
    for(u=0;u<n;u++)printf("%d %d %d\n",u+1,d[u],f[u]);
}

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

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

C++: #include <bits/stdc++.h>
#define FOR(I,X,Y) for(long int I=X;I<Y;I++)
#define REP(I,X) for(long int I=X;I>=0;I--)
#define INF 1000000007
using namespace std;

int Adj[101][101];
int d[101],f[101];

int main(){
  int n,u,k,v,t=1;
  cin >> n;
  FOR(i,0,n){
    cin >> u >> k;
    FOR(j,0,k){
      cin >> v;
      Adj[u][v] = 1;
    }
  }
  stack<int> s;
  while(1){
    bool flag2 = 1;
    FOR(i,1,n+1){
      if(d[i] == 0){
        s.push(i);
        flag2 = 0;
        break;
      }
    }
    if(flag2)break;
    while(s.size()){
      if(!d[s.top()])d[s.top()] = t;
      bool flag = 0;
      FOR(i,1,n+1)if(Adj[s.top()][i] && !d[i]){
        s.push(i);
        FOR(j,1,n+1)Adj[j][i] = 0;
        flag = 1;
        break;
      }
      t++;
      if(!flag){
        f[s.top()] = t;
        s.pop();
      }
    }
    t++;
  }
  FOR(i,1,n+1)cout << i << " " << d[i] << " " << f[i] << endl;
}

C++: 
#include <iostream>
#include <cmath>
#include <vector>
#include <string>
#include <map>
#include <algorithm>
#include <tuple>
#include <set>
#include <stack>
#include <queue>
#include <functional>


using namespace std;
using ll = long long;
using ull = unsigned long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using pii = pair<int, int>;
using vpii = vector<pii>;
using pci = pair<char, int>;
using vpci = vector<pci>;
using vb = vector<bool>;
#define out(S) cout<<(S)<<endl;
#define REP(i,b) for(int i=0;i<(b);i++)
#define rREP(i,b) for(int i=(b)-1;i>=0;i--)
#define FOR(i,a,b) for(size_t i=(a);i<(b);i++)
#define rFOR(i,a,b) for(int i=(a)-1;i>=(b);i--)
#define Foreach(item,collection) for(auto item:collection)
#define mod(i) ((i) % (ll)(1e9 + 7))
ll modpow(ll i, ll j) { ll tmp = 1; while (j) { if (j % 2)tmp = mod(tmp*i); i = mod(i*i); j /= 2; }return tmp; }
#define divmod(a,b) (mod(a * modpow((ll)b,(ll)(1e9 + 5))))
#define Yes out("Yes")
#define No out("No")
#define NO out("NO")
#define YES out("YES")
#define INF 1e10;
#define ShowAll(collection) for(auto i:collection){out(i);}
#define IfOut(condition,text) if((condition)){out(text);return 0;}
#define IfeOut(condition,itext,etext) if(condition){out(itext);return 0;}else{out(etext);return 0;}
#define GetAuto(_N,vect) {cin>>_N;vect.resize(_N);REP(i,_N){cin>>vect[i];}}
#define beginend(vec) (vec).begin(),(vec).end()
#define pb(item) push_back(item)
#define removeAll(vec,deleg) auto itr=remove_if(beginend(vec),deleg);vec.erase(itr,vec.end());
void removeAt(string& s, int index) { s.erase(index, 1); }
template<typename T> void removeAt(vector<T>& v, int index) { v.erase(v.begin() + index); }
ll manhattanDistance(ll x1, ll y1, ll x2, ll y2) { return (abs(x2 - x1) + abs(y2 - y1)); }
vector<ll> sieveOfEratosthenes(int max) { ll prime; double sqrtmax = sqrt(max); vector<ll> primeVec, searchVec; FOR(i, 2, max + 1) searchVec.push_back(i); do { prime = searchVec[0]; primeVec.push_back(prime); auto itr = remove_if(beginend(searchVec), [=](ll x)->bool {return x%prime == 0; }); searchVec.erase(itr, searchVec.end()); } while (prime < sqrtmax); primeVec.reserve(primeVec.size() + searchVec.size()); primeVec.insert(primeVec.end(), beginend(searchVec)); return primeVec; }
bool isPrime(ll x) { if (x == 2) return true; if (x < 2 || x % 2 == 0) return false; ll i = 3; while (i <= sqrt(x)) { if (x%i == 0) return false; i += 2; }return true; }
vi seq(int max, int start = 0) {vi rt(max - start+1);FOR(i, start, max+1) rt[i] = i;return rt;}
template<typename T> size_t find_first_of(vector<T> v, T val) { auto itrfind = find(beginend(v), val); size_t dis = distance(v.begin(), itrfind); if (dis == v.size()) { return -1; }return dis; }
template<class T> struct Identity {typedef T type;};
template<typename T> vector<T> select(const vector<T> &v, typename Identity<function<T(const T &)>>::type ft) {vector<T> rt; for (T item : v) { rt.push_back(ft(item)); }return rt;}
template<typename T> string join(const vector<T> &v, typename Identity<function<string(const T &)>>::type ft) {string rt = "";Foreach(x, v) {rt += ft(x);}return rt;}

vi d(100,0), f(100,0);
int time = 1;
int N;
void dfs(vvi & box,int v) {
	if (d[v] != 0) return;
	d[v] = time++;
	for (int i = 0; i < N; i++) if (box[v][i] != 0) {
		dfs(box,i);
	}
	f[v] = time++;
	return;
}

int main(){
	cin >> N;
	vvi box(N, vector<int>(N, 0));
	REP(i, N) {
		int v, k, u;
		cin >> v >> k;
		REP(n, k) {
			cin >> u;
			box[i][u-1] = 1;
		}
	}
	dfs(box, 0);

	REP(i, N) {
		cout << i + 1 << " " << d[i] << " " << f[i] << endl;
	}

	return 0;
}