Go: package main

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

type TimeRecord struct {
	discoverTime int
	finishTime   int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	timeRecordMap := make([]TimeRecord, n)
	childrenMap := make([][]int, n)
	for i := 1; i <= n; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		timeRecordMap[node-1] = TimeRecord{-1, -1}

		childNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		childrenMap[node-1] = make([]int, childNum)
		for j := 0; j < childNum; j++ {
			child, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			childrenMap[node-1][j] = child
		}
	}

	timer := 1
	for {
		startNode := findStartNode(childrenMap, timeRecordMap)
		if startNode > 0 {
			visit(startNode, &timer, childrenMap, timeRecordMap)
		} else {
			break
		}
	}
	for k, v := range timeRecordMap {
		fmt.Printf("%d %d %d\n", k+1, v.discoverTime, v.finishTime)
	}
}

func findStartNode(childrenMap [][]int, timeRecordMap []TimeRecord) int {
	x := -1
	for node, timeRecord := range timeRecordMap {
		if timeRecord.discoverTime < 0 {
			x = node + 1
			break
		}
	}
	if x < 0 {
		return -1
	}

	found := false
	i := 0
	for i < len(childrenMap) {
		children := childrenMap[i]
		for j := 0; j < len(children); j++ {
			if children[j] == x {
				x = j + 1
				found = true
				break
			}
		}
		if found {
			i = 0
		} else {
			i++
		}
	}
	return x
}

func visit(currentNode int, timer *int, childrenMap [][]int, timeRecordMap []TimeRecord) {
	if timeRecordMap[currentNode-1].discoverTime > 0 {
		return
	}
	children := childrenMap[currentNode-1]
	timeRecordMap[currentNode-1] = TimeRecord{*timer, timeRecordMap[currentNode-1].finishTime}
	(*timer)++
	for i := 0; i < len(children); i++ {
		visit(children[i], timer, childrenMap, timeRecordMap)
	}
	timeRecordMap[currentNode-1] = TimeRecord{timeRecordMap[currentNode-1].discoverTime, *timer}
	(*timer)++
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

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

class Graph {
protected:
	vector< vector<int> > adjl;
public:
	Graph(int n) : adjl(n){}
	void PushAdjl(int pl, int val) { adjl[pl].push_back(val); }
};

class DFGraph : public Graph {
private:
	int t;
	vector<int> d, f;
public:
	DFGraph(int n) : Graph(n), d(n), f(n) {}
	void DepthFirstSearch(int);
	void DFSSub(int);
	void Showdf();
};

void DFGraph::DepthFirstSearch(int begin = 0) {
	t = 1;
	DFSSub(begin);
	for (int i = 0; i < d.size(); i++)
		if (d[i] == 0)
			DFSSub(i);
}

void DFGraph::DFSSub(int v) {
	d[v] = t;
	t++;
	for (auto&& i : adjl[v])
		if (d[i] == 0)
			DFSSub(i);
	f[v] = t;
	t++;
}

void DFGraph::Showdf() {
	for (int i = 0; i < d.size(); i++)
		cout << i + 1 << " " << d[i] << " " << f[i] << endl;
}

int main() {
	int n;
	cin >> n;
	DFGraph dfg(n);
	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			int t;
			cin >> t;
			dfg.PushAdjl(u - 1, t - 1);
		}
	}
	dfg.DepthFirstSearch();
	dfg.Showdf();
}

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

int m[101][101];
int visit[101];
int d[101];
int f[101];
int n, t;

void dfs(int u){
  visit[u] = 1;
  d[u] = t;
  t++;
  
  for(int i = 0; i < n; ++i){
    if(m[u][i] == 1 && visit[i] == 0){
      dfs(i);
    }
  }

  f[u] = t;
  t++;
}

main()
{
  int 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;
      v--;
      m[u][v] = 1;
    }
  }

  for(int i = 0; i < n; ++i){
    if(visit[i]==0){
      t=1;
      dfs(i);
    }
  }

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

  return (0);
}

C++: #include <iostream>
#include<stack>
#include<vector>
using namespace std;
int main(void){
    int n ,i,DP[1001][1001],num,p,k,f[101][3],ptr=1,v;
    stack<int> s;
        cin>>n;
    for(i=1;i<=n;i++){
        cin>>p>>k;
        for(int j=1;j<=k;j++){
            cin>> num;
            DP[i][num]=1;
        }
    }
    for(i=1;i<=n;i++){
        DP[0][i]=1;
    }
    s.push(0);
    while(!s.empty()){
        v=s.top();
        for(int i=1;i<=n;i++){
            if(DP[v][i]==1&&f[i][0]==0){
                    s.push(i);
                    f[i][0]=1;
                    f[i][1]=ptr;
                    goto Exit;
            }
        }
        s.pop();
        f[v][2]=ptr;
        Exit:;
        ptr++;
    }
    for(int i=0;i<n;i++){
        cout<<i+1<<" "<<f[i+1][1]<<" "<<f[i+1][2]<<endl;
    }
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int n;
int t;
vector< vector<int> > A;
vector<int> c;
vector<int> d;
vector<int> f;

void dfsVisit(int u) {
    t++;
    d[u] = t;
    c[u] = 1;
    for(int i=0; i<A[u].size(); i++) {
        int v = A[u][i];
        if(c[v] == 0) dfsVisit(v);
    }
    t++;
    f[u] = t;
}

void dfs() {
    for(int u=0; u<n; u++) c[u] = 0;
    t = 0;
    for(int u=0; u<n; u++) {
        if(c[u] == 0) {
            dfsVisit(u);
        }
    }
}

int main() {
    cin >> n;
    A.resize(n);
    c.resize(n);
    d.resize(n);
    f.resize(n);

    for(int i=0; i<n; i++) {
        int u,k;
        cin >> u >> k;
        A[u-1].resize(k);
        for(int j=0; j<k; j++) {
            int v;
            cin >> v;
            A[u-1][j] = v-1;
        }
        sort(A[u-1].begin(), A[u-1].end());
    }

    dfs();
    for(int i=0; i<n; i++) cout << i+1 << " " << d[i] << " " << f[i] << endl;
}

C++: #include <iostream>

using namespace std;

int adja[101][101];
int d[101], f[101], cnt;

void dfs(int u) {
    d[u] = ++cnt;
    for (int i = 0, v; (v = adja[u][i]) > 0; ++i) {
        if (v > 0)
            continue;
        dfs(v);
    }
    f[u] = ++cnt;
}

int main() {
    int n, k, u;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        cin >> u >> k;
        for (int j = 0; j < k; ++j) {
            cin >> adja[u][j];
        }
    }
    for (int i = 1; i <= n; ++i) {
        if (d[i] == 0)
            dfs(i);
        cout << i << " " << d[i] << " " << f[i] << endl;
    }

    return 0;
}

C++: #include <bits/stdc++.h>
#define REP(i,n) for (int i=0;i<(n);i++)
#define All(v) (v).begin(),(v).end()
#define mp(a,b) make_pair(a,b)
#define pb(a) push_back(a)
using namespace std;
typedef long long llint;
typedef pair<int, int> P;
const int MOD = (int)1e9 + 7;
const int INF = 999999999;

int N;
int tt = 0;
vector< vector<int> > G;
vector<int> H, d, f;
int itrNum[100001];
stack<int> S;

void dfs(int u){
    S.push(u);
    H[u] = 0;

    while(!S.empty()){
        u = S.top();  // ?¨????????????????
        if(d[u] == 0) d[u] = ++tt;
        auto itr_v = next(G[u].begin(), itrNum[u]);
        if(itr_v != G[u].end()){
            itrNum[u]++;
            int v = *itr_v;
            if(H[v] == -1){
                H[v] = 0;
                S.push(v);
            }
        }else{
            S.pop();
            H[u] = 1;
            f[u] = ++tt;
        }
    }
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> N;
    G = vector<vector<int> >(N);
    H = vector<int>(N, -1);
    d = vector<int>(N, 0);
    f = vector<int>(N, 0);
    memset(itrNum, 0, sizeof(itrNum));
    REP(i, N){
        int u,k;
        cin >> u >> k;
        u--;
        REP(j ,k){
            int v;
            cin >> v;
            v--;
            G[u].pb(v);
        }
    }

    REP(i, N) if(H[i] == -1) dfs(i);
    REP(i, N){
        cout << i+1 << " " << d[i] << " " << f[i] << "\n";
    }
    return 0;
}