Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	f         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes] = &DirectedGraphNode{}
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].f = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

var time = 0

func fillDistancesByDepthFirstSearch(g *DirectedGraph) {
	for _, u := range g.nodes[1:] {
		if !u.visited {
			dfsVisit(g, u)
		}
	}
}

func dfsVisit(g *DirectedGraph, u *DirectedGraphNode) {
	time++
	u.d = time

	u.visited = true
	for _, v := range u.adjacents {
		if !v.visited {
			v.parent = u
			dfsVisit(g, v)
		}
	}
	time++
	u.f = time
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	fillDistancesByDepthFirstSearch(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		fmt.Println(node.key, node.d, node.f)
	}
}

C++: #if 0
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#endif
#include <iostream>
#include <queue>
using namespace std;
int D[105] = {0};
int V[105];
queue<int> Q[105];
int Ntime=0;
int n,u,k,v;
int d[105] = {0};//start time
int f[105] = {0};//end time
void dfs(int cur) { // cur????¨????
  // cur ????¨??????????????¨????
  Ntime += 1;
  // ???????¢??????¨??¨???
  //cerr << "visiting " << cur << ' ' << Ntime << endl;
  if(D[cur] == 0)
      d[cur] = Ntime;

  for(int dst = 1; dst <= n; dst++) { // ??¨???????????? dst ????????????
    if (D[cur] == 0&&Q[cur].size()>0 && Q[cur].front() == dst && D[dst] == 0) { // cur??????dst??????????????????,dst???????¨??????????
      if(dst != cur && d[dst] == 0)
          dfs(dst);
      Q[cur].pop();
	}
      if(D[cur] == 0&&Q[cur].size()>0 && Q[cur].front() == dst && D[dst] == 1)
          Q[cur].pop();
  }
  // cur ????¨????????????????????¨????
      Ntime += 1;
    if(D[cur] == 0){
        f[cur] =  Ntime;
        D[cur] = 1;}
  // ??¢??°?????????????????????????????? (?????¢??°)
}
int main(){
  cin >> n;
  for(int i = 1; i <= n; i++){
    cin >> u >> k;
    V[i] = i;
    for(int j = 1; j <= k; j++){
      cin >> v;
      Q[u].push(v);     
    }
  }

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


}

C++: #include <cstdio>

typedef struct vertex_{
    int found;
    int d;
    int f;
}vertex;

int search(vertex *array, int (*A)[101], int id, int n, int time){
    if(array[id].found)return time;
    array[id].found=1;
    array[id].d=++time;
    for(int i=1;i<=n;i++){
        if(A[id][i])time=search(array,A,i,n,time);
    }
    array[id].f=++time;
    return time;
}

int main(){
    int i, j, n, u, k, v;
    scanf("%d",&n);
    vertex array[n+1];
    for(i=1;i<=n;i++)array[i].found=0;
    int A[101][101];
    for(i=1;i<=n;i++){
        for(j=1;j<=n;j++){
            A[i][j]=0;
        }
    }
    for(i=1;i<=n;i++){
        scanf("%d %d",&u,&k);
        for(j=0;j<k;j++){
            scanf("%d",&v);
            A[u][v]=1;
        }
    }
    int time = search(array, A, 1, n, 0);
    for(i=1;i<=n;i++)printf("%d %d %d\n",i,array[i].d,array[i].f);
    return 0;
}

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

using vvb = std::vector<std::vector<bool>>;

struct TimeStamp
{
    int discovered;
    int finished;
};

std::vector<TimeStamp> dfs(const vvb& edges)
{
    using namespace std;

    int time {1};
    const int n = edges.size();
    stack<int> st;
    vector<bool> reached(n);
    vector<TimeStamp> times(n);

    //すべての辺について行う
    for (int i = 0; i < n; ++i)
    {
        if (reached[i])
            continue;

        reached[i] = true;
        times[i].discovered = time++;
        st.push(i);
        
        //点jからつながるすべての辺を調べる
        while (!st.empty())
        {
            int top = st.top();
            for(int j = i + 1; j < n; ++j)
                if (!reached[j] && edges[top][j])
                {
                    reached[j] = true;
                    times[j].discovered = time++;
                    st.push(j);
                    break;
                }

            //その点からの探索候補がなければ前の点に戻る
            if (top == st.top())
            {
                times[top].finished = time++;
                st.pop();
            }
        }
    }

    return times;
}

void solve()
{
    using namespace std;

    int n;
    cin >> n;

    vvb edges(n, vector<bool>(n));

    //読み込み
    for (int i = 0; i < n; ++i)
    {
        int u, k;
        cin >> u >> k;

        for (int j = 0; j < k; ++j)
        {
            int v;
            cin >> v;
            edges[u - 1][v - 1] = true;
        }
    }

    auto times = dfs(edges);

    for (int i = 0; i < n; ++i)
    {
        cout << i + 1 << " " << times[i].discovered << " " << times[i].finished << endl;
    }
}

int main()
{
    solve();
    return 0;
}