Go: #include <bits/stdc++.h>
using namespace std;
static const int WHITE = 0;
static const int GRAY  = 1;
static const int BLACK = 2;
static const int N     = 100;

int n, tt;
vector<vector<int>> M(N, vector<int>(N));
vector<int> color(N), d(N), f(N);

void dfs_visit(int u) {
  color[u] = GRAY;
  d[u]     = ++tt;
  for (int v = 0; v < n; v++) {
    if (M[u][v] == 0) continue;
    if (color[v] == WHITE) { dfs_visit(v); }
  }
  color[u] = BLACK;
  f[u]     = ++tt;
}

void dfs() {
  tt = 0;

  for (int u = 0; u < n; u++) {
    if (color[u] == WHITE) dfs_visit(u);
  }
  for (int u = 0; u < n; u++) {
    printf("%d %d %d\n", u + 1, d[u], f[u]);
  }
}

int main() {
  int u, v, k;
  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;
    }
  }

  dfs();
}

C++: #include <iostream>
#include "memory.h"
#include <stack>

using namespace std;

bool matrix[100][100];
int n;

int next(int k){
	for(int i = 0; i < n; i++){
		if(matrix[k][i] == true)
			return i + 1;
	}
	return false;
}

int main(){
	int index, temp, num, current, count = 1;
	int start_end[100][2];
	stack<int> back;

	memset(matrix, 0, sizeof(matrix));
	memset(start_end, 0, sizeof(start_end));

	cin >> n;

	for(int i = 0; i < n; i++){
		cin >> index >> num;
		while(num--){
			cin >> temp;
			matrix[index-1][temp-1] = true;
		}
	}
	back.push(0);
	current = 0;
	while(true){
		while(!back.empty()){
			int r;
			r = next(current);
			if(start_end[current][0] == 0){
				start_end[current][0] = count;
				count++;
			}
			if(r){
				matrix[current][r-1] = false;
				back.push(current);
				current = r - 1;
			}
			else{
				if(start_end[current][1] == 0){
					start_end[current][1] = count;
					count++;
				}
				current = back.top();
				back.pop();
			}
		
		}
		for(int i = 0; i < n; i++){
			if(start_end[i][0] == 0 || start_end[i][1] == 0){
				back.push(i);
				break;
			}
		}
		if(back.empty())
			break;
	}
	for(int i = 0; i < n; i++){
		cout << i + 1 << " " << start_end[i][0] << " " << start_end[i][1] << endl;
	}

}

C++: #include <bits/stdc++.h>
using namespace std;

#define ll long long
#define vvi vector<vector<int>>
#define vec vector
#define pq priority_queue
#define all(v) (v).begin(), (v).end()
#define uniqueV(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());
#define rep(i, n) for (int (i) = (0); (i) < (n); ++(i))
#define repp(i, m, n) for (int (i) = (m); (i) < (n); ++(i))
#define debug(x) cerr << #x << ": " << x << endl;
#define debug2(x, y) cerr<<"("<<#x<<", "<<#y<<") = "<<"("<<x<<", "<<y<<")"<<endl;
#define debug3(x, y, z) cerr<<"("<<#x<<", "<<#y<<", "<<#z<<") = "<<"("<<x<<", "<<y<<", "<<z<<")"<<endl;
#define debugB(x, y) cerr<<#x<<": "<<bitset<y>(x) << endl;
#define line() cerr << "---------------" << endl;

const int dx[] = {1, -1, 0, 0};
const int dy[] = {0, 0, -1, 1};

template<typename T>
void printA(vector<T> &printArray, char between = ' ') {
   int paSize = printArray.size();
   for (int i = 0; i < paSize; i++) { cerr << printArray[i] << between;}
   if (between != '\n') {cerr << endl;}
}

// ------------------------------------------------------------------------------------------

int N;
vector<vector<int>> G;
int d[111], f[111];
int turn;

void dfs(int from) {
   turn++;
   for (int to : G[from]) {
      if (d[to] == 0) {
         d[to] = turn;
         dfs(to);
         turn++;
      }
   }
   if (f[from] == 0) f[from] = turn;
}

int main() {
   cin >> N;
   G = vector<vector<int>>(N);
   rep (i, N) {
      int u, k; cin >> u >> k;
      u--;
      rep (j, k) {
         int a; cin >> a;
         a--;
         G[u].push_back(a);
      }
   }

   rep (i, N) {
      sort(G[i].begin(), G[i].end());
   }

   d[0] = 1;
   turn = 1;
   dfs(0);

   rep (i, N) {
      printf("%d %d %d\n", i+1, d[i], f[i]);
   }

   return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP0(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define REP1(i,n) for(int i=1, i##_len=(n); i<=i##_len; ++i)
#define RREP0(i,n) for(int i=n-1; i>=0; --i)
#define RREP1(i,n) for(int i=n; i>=1; --i)

#define SORT(c) sort((c).begin(),(c).end())
#define whole(f,x,...) ([&](decltype((x)) whole) { return (f)(begin(whole), end(whole), ## __VA_ARGS__); })(x)
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define CLR(a) memset((a), 0 ,sizeof(a))
#define N 100

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

typedef long long LL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;

const int INTINF = 2147483647;
const LL LLINF = 9223372036854775807;
const double EPS = 1e-10;
const double PI  = acos(-1.0);

int gcd(int a,int b){return b?gcd(b,a%b):a;}
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
int M[N][N];
int n, tt, d[N], f[N];
int color[N]; //-1:unvisited, 0:visited, 1:finished
int nt[N];

#define WHITE 0
#define GRAY 1
#define BLACK 2


int next(int u){
  FOR(v, nt[u], n){
    nt[u]=v+1;
    if (M[u][v]) return v; // where v is first next_to_u
  }
  return -1;
}


void dfs_visit(int r){
  REP0(i,n) nt[i]=0;

  stack<int> S;
  S.push(r);
  color[r] = GRAY;
  d[r] = ++tt;

  while (!S.empty()) {
    int u=S.top();
    int v=next(u);
    if (v!=-1) {
      if (color[v]==WHITE) {
        color[v]=GRAY;
        d[v]=++tt;
        S.push(v);  //次のループで取り出されるu
      }
    }else{ //隣接未探索なし
      S.pop();
      color[u]=BLACK;
      f[u]=++tt;
    }
  }

}


void dfs(){
  REP0(i,n){
    color[i]=WHITE;
    nt[i]=0;
  }
  tt=0;
  REP0(i,n) if (color[i]==WHITE) dfs_visit(i);
  REP0(i,n) std::cout << i+1 << " " << d[i] << " " << f[i] << '\n';
}


void input(int n){
  int v1, v2, d;
  REP0(i,n) { REP0(j,n) M[i][j]=0; }
  REP0(i,n){
    std::cin >> v1 >> d;
    color[v1-1]=-1;
    REP0(j,d){
      std::cin >> v2; M[v1-1][v2-1]=1;
    }
  }
}


int main(int argc, char const *argv[]) {
  cin.tie(0); ios::sync_with_stdio(false);
  std::cin >> n;
  input(n);
  dfs();
  return 0;
}

C++: #include <cstdio>
int dt[101][101];
int d[101], f[101];

int n;
int t=2;
void dfs(int s){
	for(int i=1;i<=n;i++){
		if(dt[s][i]&&d[i]==0){
			d[i]=t;
			t++;
			dfs(i);
		}
	}
	f[s]=t++;
}
int main(){
	int fi, v, g;
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		scanf("%d %d",&fi,&v);
		for(int j=1;j<=v;j++){
			scanf("%d",&g);
			dt[fi][g]=1;
		}
	}
	d[1]=1;
	dfs(1);
	for(int i=1;i<=n;i++){
		printf("%d %d %d\n",i,d[i],f[i]);
	}
	return 0;
}