Go: package main

import (
	"fmt"
	"os"
	"bufio"
	"strconv"
)

var N int
var A [][]int
var t int
var color, d, f []int

const (
	WHITE = iota
	GRAY
	BLACK
)

func dfsVisit(u int) {
	color[u] = GRAY
	t ++
	d[u] = t
	for v:=0; v<N; v++ {
		if A[u][v] == 0 {
			continue
		}
		if color[v] == WHITE {
			dfsVisit(v)
		}
	}
	color[u] = BLACK
	t++
	f[u] = t
}

func dfs() {
	for u:=0; u<N; u++ {
		if color[u] == WHITE {
			dfsVisit(u)
		}
	}
	for u:=0; u<N; u++{
		fmt.Printf("%d %d %d\n", u+1, d[u], f[u])
	}
}


func nextInt(scanner *bufio.Scanner) int {
	scanner.Scan()
	num, _ := strconv.Atoi(scanner.Text())
	return num
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	N = nextInt(scanner)
	color = make([]int, N)
	d = make([]int, N)
	f = make([]int, N)
	A = make([][]int, N)
	for i:=0; i<N; i++{
		A[i] = make([]int, N)
	}
	for i:=0; i<N; i++{
		index := nextInt(scanner) - 1
		cnt := nextInt(scanner)
		for j:=0; j<cnt; j++ {
			v := nextInt(scanner) - 1
			A[index][v] = 1
		}
	}
	dfs()
}

C++: #include<iostream>
#include<vector>
using namespace std;
const int MAXN = 1000;
int n;
int d[MAXN];
int f[MAXN];
int t;
void solve(int current,vector<vector<int> > &g){
  if(d[current] > 0)return;
  t++;
  d[current] = t;
  for(int next:g[current]){
    solve(next,g);
  }
  t++;
  f[current] = t;
}

int main(){
  cin >> n;
  vector<vector<int> > g(n+1);
  for(int i = 1;i <= n;i++){
    int u,k;
    cin >> u >> k;
    for(int j = 0;j < k;j++){
      int v;
      cin >> v;
      g[i].push_back(v);
    }
  }
  solve(1,g);
  for(int i = 1;i <= n;i++){
    cout << i << ' ' << d[i] << ' ' << f[i] << endl;
  }
}

C++: /*16D8103008D 西村悠輝　nissy0507barista  alds11_B*/ 

#include<iostream>

#define MAX 110
using namespace std;

int n,v,k,u; ///超点数、頂点番号、出次数、隣接
int d[MAX], f[MAX];///タイムスタンプ
int a[MAX][MAX];
int cnt=0;
int flag[MAX]; ///通ったかどうか

void dfs(int x) {

	if (flag[x] == 1)return;
	cnt++;
	d[x] += cnt;
	flag[x] = 1;
	for (int i = 1; i <= n; i++) {
		if (a[x][i] == 1 && flag[i] == 0) dfs(i);
	}
	cnt++;
	f[x] += cnt;

}

int main(void)
{
	cin >> n;

	for (int i = 0; i < n; i++) {
		cin >> v >> k;
		for (int j = 0; j < k; j++) {
			cin >> u ;
			a[v][u]=1;
		}
	}
	
	for (int i = 1; i <= n; i++) dfs(i);

	for (int i = 1; i <= n; i++) {
		cout << i << " " << d[i] << " " << f[i] << endl;
	}

	return 0;
}

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

int n;
int g[101][101];
char c[101];
int visit[101];
int finish[101];
int main() {
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; ++j) {
            int v;
            cin >> v;
            g[u][v] = 1;
        }

    }

   stack<int> s;
    for (int l = 1; l <= n; ++l) {
        c[l] = 'w';

    }
    int time = 0;
    int start = 0;
    int v;
    while(true) {
        start++;
        if(start == n) break;
        if(c[start] == 'w') {
            time++;
            s.push(start);
            c[start] = 'g';
            visit[start] = 1;
            while (s.size() != 0) {
                time++;
                v = s.top();
                int next = -1;
                for (int i = 1; i <= n ; ++i) {
                    if(i == v) {
                        continue;
                    }
                    if(g[v][i] && c[i] == 'w') {
                        next = i;
                        break;
                    }
                }
                if(next == -1) {
                    c[v] = 'b';
                    finish[v] = time;
                    s.pop();
                } else {
                    c[next] = 'g';
                    visit[next] = time;
                    s.push(next);
                }
            }
        }
    }

    for (int m = 1; m <= n; ++m) {
        cout << m << " " << visit[m ] << " " << finish[m] << endl;

    }



    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <climits>
#include <string>
#include <vector>
#include <utility>
#include <functional>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <cassert>

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

const ll MOD = ll(1e9) + 7;
const ll INF = LLONG_MAX;
const ll MAX_N = ll(1e5) + 5;
const double EPS = 10e-8;
const double PI = 3.14159265359;

#define REP(i, n) for (ll i = 0; i < n; i++)
#define REPR(i, n) for (ll i = n; i >= 0; i--)
#define FOR(i, m, n) for (ll i = m; i < n; i++)

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

vector<int> g[101];
bool visited[101]{};
P ans[101];

int dfs(int s, int t) {
    visited[s] = true;
    ans[s].first = t;
    REP(i, g[s].size()) {
        if (visited[g[s][i]]) continue;
        t = dfs(g[s][i], t + 1);
    }
    t++;
    ans[s].second = t;
    return t;
}

int main() {
    int n;
    cin >> n;
    REP(i, n) {
        int u, m;
        cin >> u >> m;
        REP(j, m) {
            int v;
            cin >> v;
            g[u].push_back(v);
        }
    }
    for (int i = 1, T = 0; i <= n; i++) {
        if (visited[i]) continue;
        T = dfs(i, T+1);
    }

    for (int i = 1; i <= n; i++) {
        cout << i << " " << ans[i].first << " " << ans[i].second << endl;
    }
    return 0;
}

C++: // ALDS1_12_A: Depth First Search
#include <iostream>
#include <vector>
#include <algorithm>
bool debug = false;

std::vector<std::pair<int,int>> runtime_memo;
std::vector<int> vertex_stat;
std::vector<std::vector<int>> adjacency_list;
int runtime = 0;

void init() {
    int total; std::cin >> total;
    /* Resize containers */
    runtime_memo.resize(total);
    vertex_stat.resize(total);
    adjacency_list.resize(total);
    for (int i=0;i<adjacency_list.size(); i++) {
        adjacency_list.at(i).resize(total);
    }
    for (int i=0; i<adjacency_list.size(); i++) {
        for (int j=0; j<adjacency_list.at(i).size(); j++) {
            adjacency_list.at(i).at(j) = 0;
        }
    }

    /* Set adjacency_list */
    int vertex, outdegree;
    for (int i=0; i<adjacency_list.size(); i++) {
        std::cin >> vertex >> outdegree;
        for (int j=0; j<outdegree; j++) {
            int tmp; std::cin >> tmp;
            adjacency_list.at(vertex-1).at(tmp-1) = 1;
        }
    }
}

void DepthFirstSearch(int vertex) {
    int tmp_vertex = vertex -1;
    vertex_stat.at(tmp_vertex) = 1;
    runtime++;
    runtime_memo.at(tmp_vertex).first = runtime;
    for (int i=0; i<adjacency_list.at(tmp_vertex).size(); i++) {
        if (adjacency_list.at(tmp_vertex).at(i) == 1) {
            if (vertex_stat.at(i) == 0) {
                if (debug) std::cout << "DepthFirstSearch(" << i+1 << ")" << "\n";
                DepthFirstSearch(i+1);
            }
        }
    }
    vertex_stat.at(tmp_vertex) = 2;
    runtime++;
    runtime_memo.at(tmp_vertex).second = runtime;
}

int main() {
    /* Initialization */
    init();
    /* Depth first search */
    for (int i=0; i<vertex_stat.size(); i++) {
        int id = i+1;
        if (vertex_stat.at(i) == 0) {
            DepthFirstSearch(id);
        }
    }
    /* Output */
    for (int i=0; i<adjacency_list.size(); i++) {
        int id = i+1;
        std::cout << id << " ";
        std::cout << runtime_memo.at(i).first << " ";
        std::cout << runtime_memo.at(i).second << "\n";
    }
}