Go: package main

import "fmt"

type node struct {
	id, d, v int
	adj      []node
}

var n int
var seen []bool
var graph []node

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func dfs(v, t int) int {
	// fmt.Printf("dfs(v %d, t %d) en:\n", v, t)
	seen[v] = true
	graph[v].v = t
	tt := t
	for _, vv := range graph[v].adj {
		if !seen[vv.id] {
			tt = max(tt, dfs(vv.id, tt+1))
		}
	}
	graph[v].d = tt + 1
	// fmt.Printf("dfs(v %d, t %d) ex: d %d\n", v, t, graph[v].d)
	return graph[v].d
}

func main() {
	fmt.Scan(&n)
	graph = make([]node, n+1)
	for i := 1; i <= n; i++ {
		var u, k, v int
		fmt.Scan(&u, &k)
		graph[u].id = u
		// 頂点uはk個の隣接頂点を持っている
		for j := 0; j < k; j++ {
			fmt.Scan(&v)
			var t node
			t.id = v
			graph[u].adj = append(graph[u].adj, t)
		}
	}
	// fmt.Println("n", n, "graph", graph)
	seen = make([]bool, n+1)
	// t := dfs(1, 1)
	v, t := 1, 1
	done := false
	for !done {
		tt := dfs(v, t)
		done = true
		for i := range seen {
			if !seen[i] {
				done = false
				v = graph[i].id
				t = tt
				break
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, graph[i].v, graph[i].d)
	}
}

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 argc, char const *argv[])
{
    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++: #if 0

#endif

#include <iostream>
#include <vector>
using namespace std;

int n;
int t; //mytime?????????????????§???????´?
int mytime1[110],mytime2[110]; //?????§??????
int G[110][110];
int c[110];

void dfs(int cur){
	t+=1;
	mytime1[cur]=t;
	c[cur]=1;
	for(int dst=0; dst<n; ++dst){
		if(G[cur][dst]==1&&c[dst]==0){
			dfs(dst);
		}
	} 
	t += 1;
	mytime2[cur]=t;
}


int main()
{
	vector<int> v[110];
	cin>>n;
	for(int i=0;i<n;i++){
		int u,k;
		cin>>u>>k;
		for(int j=0;j<k;j++){
			int tmp;
			cin>>tmp;
			v[u].push_back(tmp);
		}
	}
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			G[i][j]=0;
		}
	}
	for(int i=1;i<n+1;i++){
		for(int j=0;j<v[i].size();j++){
			G[i-1][v[i][j]-1]=1; 
		}
	}
	for(int i=0;i<n;++i){
		dfs(i);
		cout<<(i+1)<<' '<<mytime1[i+1]<<" "<<mytime2[i+1] <<endl;
}
}

C++: 
#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <map>
#include <set>
#include <math.h>
using namespace std;
typedef long long int ll;
#define rep(i, a, n) for (ll i = a; i < (ll)(n); i++)
long long GCD(long long a, long long b) { return b ? GCD(b, a%b) : a; }
long long LCM(long long a, long long b)  {return a/GCD(a,b)*b;}
int n;
int graph[100][100];
int d[100];
int f[100];
int now=0;
int k[100];
bool beg[106];
void dfs(int p)
{
    
   beg[p-1]=true;
 //  cout<<“p”<< p<<endl;
   //if(d[p-1]==-1)
   d[p-1]=now;
  // cout<<“now “<<now<<endl;
   if(k[p-1]==0)
   {
       now++;
       f[p-1]=now;
   }
   else
   {
       for(int i=0;i<k[p-1];i++)
       {
           if(beg[graph[p-1][i]-1]==false)
           {
               now++;
               dfs(graph[p-1][i]);
           }
       }
       now++;
       f[p-1]=now;
   }
}
int main(){
   cin>>n;
   for(int i=0;i<n;i++)
   {
       beg[i]=false;
       d[i]=-1;
       f[i]=-1;
       int number;
       cin>>number;
       cin>>k[i];
       for(int j=0;j<k[i];j++)
           cin>>graph[i][j];
   }
   now=0;
   for(int i=0;i<n;i++)
   {
       if(beg[i]==false)
       {
           now++;
           dfs(i+1);
       }
   }
   for(int i=0;i<n;i++)
   {
       cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
   }
   return 0;
}

C++: #include <bits/stdc++.h>

int d[128];
int f[128];
bool c[128][128];
int n;
int t;
int checked[128];

void dfs(int i) {
  if( checked[i] ) return;
  checked[i] = true;
  t += 1;
  d[i] = t;
  for(int k = 1; k <= n; ++k) {
    if( c[i][k] ) {
      dfs(k);
    }
  }
  t += 1;
  f[i] = t;
  return;
}

int main(void) {

  for(int i = 0; i < 128; ++i) {
    for(int j = 0; j < 128; ++j) {
      c[i][j] = false;
    }
  }

  std::cin >> n;

  int u, k, v;
  for(int i = 0; i < n; ++i) {
    std::cin >> u >> k;
    for(int j = 0; j < k; ++j) {
      std::cin >> v;
      c[u][v] = true;
    }
  }

  for(int i = 1; i <= n; ++i) {
    dfs(i);
  }

  for(int i = 1; i <= n; ++i) {
    std::cout << i << " " << d[i] << " " << f[i] << std::endl;
  }
  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, Adj[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 (Adj[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++) {
			Adj[i][j] = 0;
		}
	}
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		u--;
		for (int j = 0; j < k; j++) {
			cin >> v;
			v--;
			Adj[u][v] = 1;
		}
	}
	
	dfs();
	return 0;
}

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

int a[100][100];
int n,p,q,r;
int T[100],F[100];
int Time = 0;
void dfs(int cur) {
	T[cur] = Time;
	Time += 1;
	for (int dst=0; dst < n; ++dst) {
		if(a[cur][dst] == 1 && T[dst] == -1) {
			dfs(dst);
		}
	}
	F[cur] = Time;
	Time += 1;
}

int main() {
	cin >> n;
	for (int i=0; i<n; ++i) {
		cin >> p >> q;
		T[i] = -1;
		for (int j=0; j<q; ++j) {
			cin >> r;
			a[p-1][r-1] = 1;
		}
	}
	dfs(0);
	for (int i=0; i<n; ++i) {
		cout << i+1 << " " << T[i]+1 << " " << F[i]+1 << endl;
	}
}