Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)
	g := make([][]int, n+1)
	for i := 0; i < n; i++ {
		var u,k int
		fmt.Scan(&u)
		fmt.Scan(&k)
		g[u] = make([]int, k)
		for j := 0; j < k; j++ {
			fmt.Scan(&g[u][j])
		}
	}

	d := make([]int, n+1)
	f := make([]int, n+1)
	t := 1
	for i := 1; i <= n; i++ {
		t = dfs(&g, &d, &f, i, t)
	}

	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, d[i], f[i])
	}
}

func dfs(g *[][]int, d *[]int, f *[]int, id int, t int) int {
	if (*d)[id] > 0 {
		return t
	}
	(*d)[id] = t
	t += 1
	for i := 0; i < len((*g)[id]); i++ {
		t = dfs(g, d, f, (*g)[id][i], t)
	}
	(*f)[id] = t
	return t+1
}

C++: /**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author champon
 */

#include <iostream>
#include <fstream>
#include<bits/stdc++.h>
#define se cout << "test ok" << endl;
#define sp << " " <<
#define enl "\n"
using namespace std;
using ll=long long;
using ld=long double;
ll mod = ll(1e9)+7;
ll inf = ll(1e18);
void bl(bool b, ostream& out=cout){ out << (b ? "Yes" : "No") << endl; }
void bl2(bool b, ostream& out=cout){ out << (b ? "YES" : "NO") << endl; }
template<typename T> inline bool chmax(T &a, T b){ if(a<b){a=b; return true;} return false; }
template<typename T> inline bool chmin(T &a, T b){ if(a>b){a=b; return true;} return false; }
int dx[] = {1, 0, -1, 0, 1, -1, 1, -1};
int dy[] = {0, 1, 0, -1, 1, -1, -1, 1};

#ifndef INCLUDE_DEBUG_HPP
#define INCLUDE_DEBUG_HPP

#include <iostream>
#include <vector>
#include <map>
using namespace std;

namespace dbg {
    using ll = long long;

    class Debug {
    public:
        Debug(){}
        template<typename T>
        void vd(vector<T> vec);
        template<typename T>
        void vd2(vector<vector<T>> vec);
        template<typename T>
        void ad(T *arr, ll n);
        template<typename T, size_t N>
        void ad2(T (&arr)[N], ll n);
        template<typename T>
        void md(T mp);
    };

    template<typename T>
    void Debug::vd(vector<T> vec) {
        for (auto vv : vec) cout << vv << " ";
        cout << endl;
    }

    template<typename T>
    void Debug::vd2(vector<vector<T>> vec) {
        for (auto vv : vec) {
            for (auto vvv : vv) cout << vvv << " ";
            cout << endl;
        }
    }

    template<typename T>
    void Debug::ad(T *arr, ll n) {
        for (int i = 0; i <= n; i++) cout << arr[i] << " ";
        cout << endl;
    }

    template<typename T, size_t N>
    void Debug::ad2(T (&arr)[N], ll n) {
        for (int i = 0; i <= N; i++) for (int j = 0; j <= n; j++) cout << arr[i][j] << " ";
        cout << endl;
    }

    template<typename T>
    void Debug::md(T mp) {
        cout << "key : value" << endl;
        for (auto const &m : mp) cout << m.first << " : " << m.second << endl;
        cout << endl;
    }

}

#endif //INCLUDE_DEBUG_HPP

using dbg::Debug;
Debug debug;

class dfs {
public:
    vector<set<int>> g;
    vector<int> d, f;

    int rec(int u, int cnt){
        d[u] = cnt;

        for(auto& to : g[u]){
            if(d[to]) continue;
            cnt = rec(to, cnt+1);
        }

        f[u] = ++cnt;
        return cnt;
    }

	void solve(std::istream& in, std::ostream& out) {
	    int n;
	    in >> n;
	    int u, k;
	    g.assign(n, set<int>());
	    for(int i=0; i<n; i++){
            in >> u >> k;
            int v;
            --u;
            for(int j=0; j<k; j++){
                in >> v;
                --v;
                g[u].insert(v);
            }
	    }

        d.assign(n, 0);
        f.assign(n, 0);

        bool flg = false;
        int start = 0;
        int cnt = 0;
        while(!flg) {
            cnt = rec(start, cnt+1);
            start = -1;
            for(int i=0; i<n; i++){
                if(!d[i]){
                    start = i;
                    break;
                }
            }
            if(start == -1) flg = true;
        }

        for(int i=0; i<n; i++){
            out << i+1 sp d[i] sp f[i] << enl;
        }
	}
};


int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
	dfs solver;
	std::istream& in(std::cin);
	std::ostream& out(std::cout);
	solver.solve(in, out);
	return 0;
}

C++: #include <iostream>
using namespace std;
 
int visit[100],end[100],a[100][100];
int t,N,u,k,p;
 
void list(int N){
    for(int i=0;i<N;i++){
        cin>>u>>k;
        for (int j=0;j<k;j++){
            cin>>p;
            a[u-1][p-1]=1;
        }
    }
}
 
void sor(int cur,int N){
    t+=1;
    visit[cur]=t;
    for(int kyo=0;kyo<N;++kyo){
        if(a[cur][kyo]==1&&visit[kyo]==0){
            sor(kyo,N);
        }
    }
    t+=1;
    end[cur]=t;
}
 
int main(){
    cin >> N;
    list(N);
    for(int i=0;i<N;i++){
        if(visit[i] == 0) sor(i,N);
    }
    for(int i=0;i<N;i++){
        cout<<i+1<<' '<<visit[i]<<' '<<end[i]<<endl;
    }
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>
 
#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
 
using namespace std;
 
typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;
 
const int INF=1<<29;
const double EPS=1e-9;
 
const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};

std::vector<vector<int> > G;
std::vector<int> flag;
std::vector<int> in;
std::vector<int> out;
int N;
int dfs(int u, int count) {
	if (flag[u] == 1) return -1;
	flag[u] = 1;
	
	in[u] = count;
	for (int i = 0; i < N; ++i) {
		if (flag[i] == 0 && G[u][i] == 1) {
			count = dfs(i, count + 1);
		}
	}
	out[u] = count + 1;
	return count + 1;
}

int main(int argc, char const *argv[]) {
	
	cin >> N;

	for (int i = 0; i < N; ++i) {
		G.push_back(vector<int>());
		flag.push_back(0);
		in.push_back(0);
		out.push_back(0);
		for (int j = 0; j < N; ++j) {
			G[i].push_back(0);
		}
	}

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

	int count = 1;
	for(int i = 0; i < N; i++) {
		int r = dfs(i, count);
		if (r != -1) {
			count = r + 1;
		}
	}

	for (int i = 0; i < N; ++i) {
		cout << i + 1 << " " << in[i] << " " << out[i] << endl;
	}

	return 0;
}

C++: #include <iostream>
#include <stack>

using namespace std;

static const int N = 100;
static const int YET = 0;
static const int ALREADY = 1;

int state[N];
int timeTable[N][2];
int timeCount = 0;
int currentV;
stack<int> st;
int M[N][N];

void travel() {
  while(!st.empty()) {
    currentV = st.top();
    st.pop();

    if(state[currentV] == YET) {
      timeCount++;
      timeTable[currentV][0] = timeCount;
      state[currentV] = ALREADY;
      st.push(currentV);

      for(int i = N; i > -1; i--) {
        if(M[currentV][i] == 1 && state[i] == YET) {
          st.push(i);
        }
      }
    }
    else if(timeTable[currentV][1] == 0){
      timeCount++;
      timeTable[currentV][1] = timeCount;
    }
  }
}
int main(void) {


  int n, u, k, v;

  cin >> n;

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

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

  st.push(0);
  travel();
  for(int i = 0; i < N; i++) {
    if(state[i] == YET) {
      st.push(i);
      travel();
    }
  }


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