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++: #include <iostream>
#include <algorithm> // next_permutation
#include <iomanip>
#include <cmath>
#include <vector>
#include <sstream>
#include <string>
#include <cstdio>
#include <stack>
#include <queue>
#include <list>
#include <numeric> //accumulate
//#include <unordered_map> //???????????\??¢??°
#include <fstream> //ifstream, ofstream

//#define NDEBUG //NDEBUG???#include <cassert>???????????????????????????????????´???assert?????????????????????????????????NDEBUG?????????????????????????????????????????????
#include <cassert> //assert


using namespace std;

//???????????°??????TEST????????????????????¬???????????????????????????????????¢????????????
#define TEST //*******************************************************************************************************************************************
//?????????????????¨??§?????\????????????????????????????????°?????????????¨???????????????????dout???????????????????????§???????????¬??????????????????????????????????????????
//??????????????????????????????????????????????????????????§?CPU???????£??????????????????§???TLE?????????????????????????????????????????§????????¨???                           ????????????????????????cerr????????£????????????????????????????????????
#ifdef TEST
#define dout cout
#define din cin
#else
stringstream dummy; //???????????°??????dout?????????????????????????????????
#define dout dummy.str(""); dummy.clear(stringstream::goodbit); dummy //dummy?????????????????????????????????????????¨?????¢?????¢???????????????
//???????????¨??????????????????goodbit?????????????????????????????¨???????????´????????????????????????????????¨?????°?????????????????§???????????????????????????????????? http://d.hatena.ne.jp/linden/20060427/p1
#endif

//?¨??????????????????????????????????????????????????????´??????OUTPUTFILE????????????????????¬???????????????????????????????????¢????????????
//#define OUTPUTFILE "output.txt" //*******************************************************************************************************************************************
#ifdef OUTPUTFILE
#define dout outputfile //??¨????????????TLE????????§?????????dout?????¨??¨??????????????¢????????????????????????????????????????????§????¨????????????´??????????????£??????????????????????¨?????????????????????????????????????????????§?????????????????????
ofstream outputfile(OUTPUTFILE);
#define OutputFilePath "/Users/Nag/Documents/Prgm/Test/DerivedData/Test/Build/Products/Debug/output.txt"
#endif

//?¨??????\???????????????????????????????????????????????´??????INPUTFROMTEXTFILE????????????????????¬???????????????????????????????????¢????????????
//#define INPUTFILE "input.txt" //*******************************************************************************************************************************************
#ifdef INPUTFILE
#define din inputfile
ifstream inputfile(INPUTFILE);
#endif


#define disp(A) dout << #A << " = " << (A) << endl
#define disP(A) dout << setw(3) << (A) << " " // << setw(3) ??????????????\????????????
#define rep(i,a,n) for(int (i)=(a); (i)<(n); (i)++)
#define dispAll(A,n) dout << #A << " = "; rep(j, 0, (n)) {disP(A[j]);} dout << endl

typedef pair<int,int> pii;
typedef vector<int> vi;
typedef unsigned long long ll;


const int INF = 999;//1e9-1;

int n;

//all array 1-based index
bool adjacencyMatrix[101][101] = {0};
int adjacencyList[101][101] = {0};

int currentTime = 1;
int discoveredTime[101] = {0};
int finishedTime[101] = {0};

int currentNode = 1;


void dfs(int src, int i) {
//    disp(src); disp(i);
//    dispAll(discoveredTime, n+3);
//    dispAll(finishedTime, n+3);
    
    if(discoveredTime[i]!=0) return;
    
    discoveredTime[i]=currentTime++;
    
    int j = 1;
    while(adjacencyList[i][j] != 0) {
//        disp(j);
//        disp(adjacencyList[i][j]);
        
        assert(j<=n);
        //??????????????¨??¨??§n?????§??????????????¨??????????????¨??????????????????list????????§??§???n-1??????????????°???????????§???0???n-1?????§???????????°??????adjacencyList[i][n]????????¶???0???????????????
        
        dfs(src, adjacencyList[i][j]);
        j++;
    }
    
    finishedTime[i] = currentTime++;
    
    
    //find next src
    if(src==i) {
//        dout<<"src==i\n";
        int k=1;
        while(discoveredTime[k]!=0) k++;
        
        if(k==n+1) {
//            dout<<"end\n";
            return; //??¨???????????¢?´¢??????
        }
        else {
//            dout<<"new src\n";
            src = k;
            dfs(src,src);
        }
    }
    
    return;
}



int main() {
    din>>n;
    
    int s, g, numOfAdjacent;
    
    
    //input
    rep(i,1,n+1) {
        din>>s>>numOfAdjacent;
        
        rep(j,1,numOfAdjacent+1) {
            din>>g;
            adjacencyMatrix[s][g] = 1;
            adjacencyList[s][j] = g;
        }
    }
    
//    //test display
//    dout<<"   dist = ";
//    rep(j,1,n+1) dout<<j<<" ";
//    dout<<endl;
//    dout<<"          ";
//    rep(j,1,n+1) dout<<"-"<<" ";
//    dout<<endl;
//    
//    rep(i,1,n+1) {
//        dout<<"src = "<<i<<" | ";
//        rep(j,1,n+1) {
//            dout<<(j==1?"":" ")<<adjacencyMatrix[i][j];
//        }
//        dout<<endl;
//    }
//    
//    dout<<endl;
//    dout<<"                       ";
//    rep(j,0,n+1) disP(j);
//    dout<<endl;
//    dout<<"                       ";
//    rep(j,0,n+1) dout<<"  - ";
//    dout<<endl;
//    rep(i,1,n+1) {
//        disP(i); dispAll(adjacencyList[i], n+1);
//    }
    
    
    
    //DFS (Depth First Search)
    dfs(1,1);

//    dispAll(discoveredTime, n+1);
//    dispAll(finishedTime, n+1);
    
    
    //output
    rep(i,1,n+1) {
        dout<<i<<" "<<discoveredTime[i]<<" "<<finishedTime[i]<<endl;
    }
    
    
#ifdef INPUTFILE
    inputfile.close();
#endif
    
#ifdef OUTPUTFILE
    outputfile.close();
    cout << "\"" << OutputFilePath << "\"" << endl;
#endif
    
    return 0;
}

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

vector< vector< int > > adjList;
vector< int > d, f;

void dfs(int id) {
  static int time = 1;
  if (!d[id-1]) {
    d[id-1] = time++;
    for (int i = 0; i < adjList[id-1].size(); i++)
      dfs(adjList[id-1][i]);
    f[id-1] = time++;
  }
}

int main(int argc, char **argv) {
  ios_base::sync_with_stdio(false);
  int n;
  cin >> n;
  adjList = vector< vector< int > > (n, vector< int > ());
  d = vector< int > (n, 0);
  f = vector< int > (n, 0);
  for (int i = 0; i < n; i++) {
    int id, k;
    cin >> id >> k;
    for (int j = 0; j < k; j++) {
      int holder;
      cin >> holder;
      adjList[id-1].push_back(holder);
    }
  }
  for (int i = 0; i < n; i++)
    if (!d[i])
      dfs(i+1);
  for (int i = 0; i < n; i++)
    cout << i+1 << ' ' << d[i] << ' ' << f[i] << endl;
  return 0;
}