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 <bits/stdc++.h>
#define pb push_back
using namespace std;

int num = 1;
bool visited[1000];
vector<int> v[1000], seq[1000];
void dfs(int k){
    seq[k].pb(num++);
    if(visited[k]) return;
    visited[k] = 1;
    for (auto t : v[k]){
        if(visited[t]) continue;
        dfs(t);
    }
    seq[k].pb(num++); return;

}
int main(){
    int n; cin >> n;
    memset(visited, 0, sizeof(visited));
    for (int i = 0; i < n; i++){
        int x, y, z; cin >> x >> y;
        for (int j = 0; j < y; j++){
            cin >> z; v[x].pb(z);
        }
    }
    for(int i = 1; i <= n; i++)
        sort(v[i].begin(), v[i].end());
    dfs(1);
    for (int i = 1; i <= n; i++){
        cout << i << ' ';
        for (auto k : seq[i])
        cout << k << ' ';
        cout << '\n';
    }
}

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

using namespace std;

struct Node {
    bool visit = false;
    vector<int> next;
    int position = 0;
    int start = 0;
    int end = 0;
};

int main() {
    int n, id, k, temp, time = 1;
    Node node[101];
    stack<int> st;

    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> id >> k;
        for (int j = 0; j < k; j++) {
            cin >> temp;
            node[id].next.push_back(temp);
        }
    }

    while (1) {
        int s = -1;
        for (int i = 1; i <= n; i++) {
            if (node[i].start == 0) {
                s = i;
                break;
            }
        }
        if (s == -1) {
            break;
        }
        
        node[s].start = time++;
        st.push(s);
        while (!st.empty()) {
            temp = st.top();
            if (node[temp].position < node[temp].next.size() && node[node[temp].next[node[temp].position]].visit == false) {
                node[node[temp].next[node[temp].position]].start = time++;
                st.push(node[temp].next[node[temp].position++]);
            }
            else {
                node[temp].visit = true;
                node[temp].end = time++;
                st.pop();
            }
        }
    }

    for (int i = 1; i <= n; i++) {
        cout << i << " " << node[i].start << " " << node[i].end << endl;
    }

    return 0;
}

C++: #include <iostream>
#include <stdio.h>
#include <string>
using namespace std;

#define N 105

struct Node{
    string color;
    int d;
    int f;
};

struct Node node[N];
int tt;
int AdjMat[N][N];

void DFS(int u, int n){
    node[u].color = "gray";
    node[u].d = ++tt ;
    for (int v = 1; v <= n; v++){
        if ( AdjMat[u][v] == 0 ) continue;
        if ( node[v].color == "white") DFS(v, n);
    }
    node[u].color = "black";
    node[u].f = ++tt;
}

void DFS_init(int n){
    for (int i = 1; i <= n; i++){
        node[i].color = "white";
    }
    tt = 0;
    
    for (int i = 1; i <= n; i++){
        if (node[i].color == "white") DFS(i, n);
    }
    for (int i = 1; i <= n; i++){
        printf("%d %d %d\n", i, node[i].d, node[i].f);
    }
}

int main(){
    
    int n;
    cin >> n;
    
    for (int i = 1; i <= n; i++ ){
        for (int j = 1; j <= n; j++){
            AdjMat[i][j] = 0;
        }
    }
    
    for (int i = 1; i <= n; i++){
        int u, k, v;
        cin >> u >> k;
        if ( k == 0 ) continue;
        for (int j = 1; j <= k; j++){
            cin >> v;
            AdjMat[u][v] = 1;
        }
        
    }
    DFS_init(n);
    
    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; //time stomp

    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;

#define MAX 110
int num;
int matrix[MAX][MAX];
int dst[MAX];

void input(){
    cin >> num;
    for(int i=0;i<MAX;i++){
        dst[i] = -1;
        for(int j=0;j<MAX;j++){
            matrix[i][j] = 0;
        }
    }
    for(int i=1;i<=num;i++){
        int v; cin >> v;
        int tmp; cin >>tmp;
        for(int j=0;j<tmp;j++){
            int vi; cin >> vi;
            matrix[v-1][vi-1] = 1;
        }
    }
}

void dfs(){
    stack<int> S;
    S.push(0);
    dst[0] = 0;
    while(!S.empty()){
        int cur = S.top();
        S.pop();
        if(dst[cur]==-1 || dst[cur]== 0){
            for(int i=0;i<num;i++){
                if(matrix[cur][i]==1){
                    S.push(i);
                }
            }
        }
    }
    for(int i=0;i<num;i++){
        cout << i+1 << " " <<  dst[i] << endl;
    }
}

int main(){
    input();
    dfs();
}

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

int a[101][101];
int n = 0;
int found[101];
int ended[101];
int aaa(int i, int time);

int main() {
  for (int i = 0; i < 101; i++)
    for (int j = 0; j < 101; j++)
	  a[i][j] = 0;
  int u, k, v;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> u >> k;
	for (int j = 0; j < k; j++) {
	  cin >> v;
	  a[u][v] = 1;
	  }
	 }
int time = 0;
for (int i = 0; i < 101; i++){
  found[i] = 0;
  ended[i] = 0;
  }
for (int i = 0; i < n+1; i++) {
  if(found[i] > 0)
    continue;
  time++;
  found[i]=time;
  time=aaa(i,time);
  ended[i]=time;
  }
  
for (int i = 1; i < n+1; i++) {
 cout << i << ' ' << found[i] << ' ' << ended[i] << endl;
 }
}
 
int aaa(int i, int time) {
  for (int k = 1; k < n+1; k++) {
    if (a[i][k] == 1 && found[k] == 0) {
	  time++;
	  found[k] = time;
	  time = aaa(k,time);
	  ended[k] = time;
	  }
	 }
	time++;
	return time;
	}