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 "bits/stdc++.h"
#pragma GCC optimize("Ofast")

// Begin {{{
using namespace std;

#ifndef DEBUG
#define dump(...)
#endif

template <class A, class B> inline bool chmax(A &a, const B &b) { return b > a && (a = b, true); }
template <class A, class B> inline bool chmin(A &a, const B &b) { return b < a && (a = b, true); }

template <class T>
inline vector<T> make_v(const T &initvalue, size_t sz) {
    return vector<T>(sz, initvalue);
}

template <class T, class... Args>
inline auto make_v(const T &initvalue, size_t sz, Args... args) {
    return vector<decltype(make_v<T>(initvalue, args...))>(sz, make_v<T>(initvalue, args...));
}

constexpr int INF = 0x3f3f3f3f;
constexpr int64_t LINF = 0x3f3f3f3f3f3f3f3fLL;
// }}} End

size_t N;
vector<size_t> g[105];
vector<size_t> d(105), f(105);
vector<bool> seen(105);

size_t t = 0;

void dfs(size_t now_node) {
    seen[now_node] = true;
    d[now_node] = ++t;
    for (auto &next_node: g[now_node]) {
        if (!seen[next_node]) {
            dfs(next_node);
        }
    }
    f[now_node] = ++t;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> N;

    for (size_t i = 0; i < N; ++i) {
        size_t u, k; cin >> u >> k;
        u--;
        for (size_t j = 0; j < k; ++j) {
            size_t v; cin >> v;
            v--;
            g[u].emplace_back(v);
        }
    }

    for (size_t idx = 0; idx < N; ++idx) {
        if (!seen[idx]) {
            dfs(idx);
        }
    }

    for (size_t idx = 0; idx < N; ++idx) {
        cout << idx + 1 << " " << d[idx] << " " << f[idx] << "\n";
    }

    return 0;
}

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

using namespace std;
int t;

void dfs(vector<vector<bool> >& A, vector<vector<int> >& B, int s, int n){
    for(int i = 0; i < n; i++){
        if(i == 0){
            if(B[s][1] == 0){
                B[s][1] = t;
                t++;
            }
        }
        if(A[s][i] == true){
            A[s][i] = false;
            dfs(A, B, i, n);
        }
        if(i == n-1){
            if(B[s][2] == 0){
                B[s][2] = t;
                t++;
            }
        }
    }
}

int main(void){

    //??£??\??????????????£??\???????????????
    int n, k;

    cin >> n;
    vector<vector<bool> > A(n, vector<bool>(n, false));
    for(int i = 0; i < n; i++){
        cin >> k >> k;
        for(int j = 0; j < k; j++){
            int input;
            cin >> input;
            A[i][input-1] = true;
        }
    }

   

    vector<vector<int> > B(n, vector<int>(3, false));
    for(int i = 0; i < n; i++){
        B[i][0] = i + 1;
    }

    t = 1;
    for(int k = 0; k < n; k++){
        if(B[k][1] == 0) dfs(A, B, k, n);
    }
    

    //??????
    for(int i = 0; i < n; i++){
        for(int j = 0; j < 3; j++){
            if(j != n-1) cout << B[i][j] << " ";
            else cout << B[i][j];
        }
        cout << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>	// require sort next_permutation count __gcd reverse etc.
#include <cstdlib>	// require abs exit atof atoi 
#include <cstdio>		// require scanf printf
#include <functional>
#include <numeric>	// require accumulate
#include <cmath>		// require fabs
#include <climits>
#include <limits>
#include <cfloat>
#include <iomanip>	// require setw
#include <sstream>	// require stringstream 
#include <cstring>	// require memset
#include <cctype>		// require tolower, toupper
#include <fstream>	// require freopen
#include <ctime>		// require srand
#define rep(i,n) for(int i=0;i<(n);i++)
#define ALL(A) A.begin(), A.end()

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

bool adj[105][105];
bool vis[105];
struct node{
	int ft;
	int rt;
};
node v[105];

int n;
int cnt;

void dfs (int cur )
{
	cnt++;
	vis[cur] = true;	
	v[cur].ft = cnt;
	for (int u = 1; u <= n; u++ ){
		if (!vis[u] && adj[cur][u] )
			dfs (u );
	} // end for
	cnt++;
	v[cur].rt = cnt;
}

int main()
{
	memset (adj, false, sizeof (adj ) );
	memset (vis, false, sizeof (vis ) );

	ios_base::sync_with_stdio(0);
	cin >> n;

	rep (i, n ) v[i].ft = 0, v[i].rt = 0;

	rep (i, n ){
		int v, k;
		cin >> v >> k;
		while (k-- ){
			int u; cin >> u;
			adj[v][u] = true;
		} // end rep
	} // end rep
	cnt = 0;
	dfs (1 );	

	for (int i = 1; i <= n; i++ ){
		cout << i << ' ' << v[i].ft << ' ' << v[i].rt << endl;
	} // end for
	
	return 0;
}