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 <algorithm>
#include <iostream>
#include <math.h>
#include <stdio.h>
#include <string>
#include <sstream>
#include <vector>
#include <set>
#include <stack>
#include <map>
#include <cmath>
#include <queue>
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
using namespace std;
typedef long long ll;
#define MAX_N 100
int d[MAX_N];
int f[MAX_N];

void init(){
	rep(i,MAX_N){
		d[i] = -1;
		f[i] = -1;
	}
}
	
int main()
{
	init();
	int n;
	cin>>n;
	vector<int> *adjList = new vector<int>[n];
	for(int i = 0; i < n; i++){
		int u;
		int k;
		cin>>u>>k;
		rep(j,k){
			int num;
			cin>>num;
			num--;
			adjList[i].push_back(num);
		}
	}
	int currentNode;
	stack<int> searchSt;
	int time = 0;
	rep(j,n){
		bool jIsDone = true;
		if(f[j] == -1){
			time++;
			searchSt.push(j);
		}else{
			continue;
		}
		while(searchSt.empty() != true){
			currentNode = searchSt.top();
			if( d[currentNode] == -1){
				d[currentNode] = time;
			}
			bool isEverythingDone = true;
			for(auto iter = adjList[currentNode].begin();iter != adjList[currentNode].end() ;iter++){
				if( d[*iter] == -1){
					time++;
					isEverythingDone = false;
					searchSt.push(*iter);
					break;
				}
			}
			if( isEverythingDone == true){
				time++;
				f[currentNode] = time;
				searchSt.pop();
			}
		}
	}
	
	rep(i,n){
		cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
	}

	return 0;
}

C++: #include <iostream>
#include <string>
#include <map>
#include <stack>
#include <algorithm>
using namespace std;
#define MAX 100000

static const int N=100;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;

int n, M[N][N];
int color[N],d[N],f[N],tt;
int nt[N];

int next(int u){
  for(int v=nt[u];v<n;v++){
    nt[u]=v+1;
    if(M[u][v]) return v;
  }
  return -1;
}

void dfs_visit(int r){
  for(int i=0;i<n;i++) 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);
      }
      else{
        S.pop();
        color[u]=BLACK;
        f[u]=++tt;
      }
    }
  }
}

void dfs(){
  for(int i=0;i<n;i++){
    color[i]=WHITE;
    nt[i]=0;
  }
  tt=0;

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

int main(){
  int u,k,v;
  cin >> n;

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

  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();
  return 0;
}

C++: #include<iostream>
#include<stack>
using namespace std;
static const int N=100;
static const int WHITE = 0;
static const int GRAY =1;
static const int BLACK=2;

int n,M[N][N];
int color[N],d[N],f[N],tt;
int nt[N];

int next(int u){
  for(int v=nt[u];v<n;v++){
    nt[u]=v+1;
    if(M[u][v])return v;
  }
  return -1;
}

void dfs_visit(int r){
  for(int i=0;i<n;i++)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);
      }
    }else{
      S.pop();
      color[u]=BLACK;
      f[u]=++tt;
    }
  }
}

void dfs(){
  for(int i=0;i<n;i++){
    color[i]=WHITE;
    //nt[i]=0;
  }
  tt=0;
  for(int u=0;u<n;u++){
    if(color[u]==WHITE)dfs_visit(u);
  }
  for(int i=0;i<n;i++){
    cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
  }
}
int main(){
  int u,k,v;

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

  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();
  return 0;
}

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

const long N = 100;
const long WHITE = 0;
const long GRAY = 1;
const long BLACK = 2;

long n, M[N + 1][N + 1];
long color[N + 1], d[N + 1], f[N + 1], tt;
long nt[N + 1];

long next(long u){
	for (long v = nt[u]; v < n; v++){
		nt[u] = v + 1;
		if (M[u][v]) return v;
	}
	return -1;
}

void dfs_visit(long r){
	for (long i = 1; i <= n; i++) nt[i] = 0;

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

	while (!S.empty()){
		long u = S.top();
		long v = next(u);
		if (v != -1){
			if (color[v] == WHITE){
				color[v] = GRAY;
				d[v] = ++tt;
				S.push(v);
			}
			else {
				S.pop();
				color[u] = BLACK;
				f[u] = ++tt;
			}
		}
	}
}

void dfs(){
	for (long i = 1; i <= n; i++){
		color[i] = WHITE;
		nt[i] = 0;
	}
	tt = 0;

	for (long u = 1; u <= n; u++){
		if (color[u] == WHITE) dfs_visit(u);
	}
	for (long i = 1; i <= n; i++){
		cout << i + 1 << " " << d[i] << " " << f[i] << endl;
	}
}

int main(){
	long u, k, v;
	cin >> n;
	for (long i = 1; i <= n; i++){
		for (long j = 1; j <= n; j++){
			M[i][j] = 0;
		}
	}

	for (long i = 1; i <= n; i++){
		cin >> u >> k;
		for (long j = 1; j <= n; j++){
			cin >> v;
			M[u][v] = 1;
		}
	}

	dfs();

	return 0;
}

C++: #include<bits/stdc++.h>
#define ll long long
#define rep(i, n) for(int i=0;i<(n);++i)
#define per(i, n) for(int i=(n)-1;i>=0;--i)
#define repa(i, n) for(int i=1;i<(n);++i)
#define foreach(i, n) for(auto &i:(n))
#define pii pair<int, int>
#define pll pair<long long, long long>
#define all(x) (x).begin(), (x).end()
#define bit(x) (1ll << (x))
const ll MOD = (ll)1e9+7;
const int INF = (ll)1e9+7;
const ll INFLL = (ll)1e18;
using namespace std;
template<class t>
using vvector = vector<vector<t>>;
template<class t>
using vvvector = vector<vector<vector<t>>>;
template<class t>
using priority_queuer = priority_queue<t, vector<t>, greater<t>>;
template<class t, class u> bool chmax(t &a, u b){if(a<b){a=b;return true;}return false;}
template<class t, class u> bool chmin(t &a, u b){if(a>b){a=b;return true;}return false;}

ll modpow(ll x, ll b){
	ll res = 1;
	while(b){
		if(b&1)res = res * x % MOD;
		x = x * x % MOD;
		b>>=1;
	}
	return res;
}

ll modinv(ll x){
	return modpow(x, MOD-2);
}

bool was_output = false;
template<class t>
void output(t a){
	if(was_output)cout << " ";
	cout << a;
	was_output = true;
}
void outendl(){
	was_output = false;
	cout << endl;
}

vvector<int> edges;
vector<int> found_time;
vector<int> finish_time;

int dfs(int place, int time){
	++time;
	found_time[place] = time;
	foreach(i, edges[place]){
		if(found_time[i]>=0)continue;
		time = dfs(i, time);
	}
	++time;
	finish_time[place] = time;
	return time;
}

int main(){
	int n;
	cin >> n;
	edges.resize(n);
	found_time.resize(n, -1);
	finish_time.resize(n, -1);
	rep(i, n){
		int t;
		int time;
		cin >> t >> time;
		--t;
		rep(j, time){
			int to;
			cin >> to;
			--to;
			edges[t].push_back(to);
		}
	}
	int time = 0;
	rep(i, n){
		if(found_time[i]<0)time = dfs(i, time);
	}
	rep(i, n){
		output(i+1);
		output(found_time[i]);
		output(finish_time[i]);
		outendl();
	}
	return 0;
}