Go: package main

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

/***************************************************************
stackによる深さ優先探索を実装する。
***************************************************************/

const (
	N     = 100
	WHITE = 0
	GRAY  = 1
	BLACK = 2
)

var (
	n            int
	Adj          [N][N]int
	statusColor  [N]int
	discoverTime [N]int
	finishTime   [N]int
	clock        int
	nt           [N]int
)

/***************************************************************
Stackの定義:
- field
	container: ノードの格納されたスライス
	sp: スタックポインタ
- method
	size(): スタックに積まれているノードの個数を返す
	top(): スタックの一番上に積まれているノードを返す
	isEmpty(): スタックが空かどうかを返す
	pop(): スタックの要素をポップし削除する
	push(): スタックに要素を積む
***************************************************************/

type Stack struct {
	container []int
	sp        int
}

func (s *Stack) size() int {
	return len(s.container)
}

func (s *Stack) top() int {
	return s.container[s.sp]
}

func (s *Stack) isEmpty() bool {
	return s.sp == 0
}

func (s *Stack) pop() int {
	_pop := func() {
		s.container = s.container[:len(s.container)-1]
	}
	defer _pop()
	if s.isEmpty() {
		panic("There is no elements in stack!")
	}
	s.sp--
	return s.container[s.sp]
}

func (s *Stack) push(n int) {
	s.sp++
	s.container[s.sp] = n
}

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

func _DFS(target int) {
	for i := 0; i < n; i++ {
		nt[i] = 0
	}
	stack := new(Stack)
	stack.container = make([]int, N)
	stack.push(target)
	statusColor[target] = GRAY
	clock++
	discoverTime[target] = clock
	for !stack.isEmpty() {
		u := stack.top()
		v := next(u)
		if v != -1 {
			if statusColor[v] == WHITE {
				statusColor[v] = GRAY
				clock++
				discoverTime[v] = clock
				stack.push(v)
			}
		} else {
			stack.pop()
			statusColor[u] = BLACK
			clock++
			finishTime[u] = clock
		}
	}
}

func DFS() {
	for i := 0; i < n; i++ {
		statusColor[i] = WHITE
		nt[i] = 0
	}
	clock = 0
	for i := 0; i < n; i++ {
		if statusColor[i] == WHITE {
			_DFS(i)
		}
	}
	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", i+1, discoverTime[i], finishTime[i])
	}
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	scanner.Scan()
	n, _ = strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			Adj[i][j] = 0
		}
	}
	for i := 0; i < n; i++ {
		scanner.Scan()
		u, _ := strconv.Atoi(scanner.Text())
		scanner.Scan()
		k, _ := strconv.Atoi(scanner.Text())
		u--
		for j := 0; j < k; j++ {
			scanner.Scan()
			v, _ := strconv.Atoi(scanner.Text())
			v--
			Adj[u][v] = 1
		}
	}

	DFS()
}

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

int n, t, G[101][101], S[101], T[101];

void dfs(int p) {
    if (S[p] != 0) return;
    S[p] = ++t;
    for (int i = 0; i < n; i++)
        if (G[p][i] == 1)
            dfs(i);

    T[p] = ++t;
}


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

    t = 0;
    for (int i = 0; i < n; i++)
        dfs(i);

    for (int i = 0; i < n; i++)
        printf("%d %d %d\n", i + 1, S[i], T[i]);

    return 0;
}

C++: #include<iostream>

using namespace std;

int A[101][100];//データを入れる配列
int d[101];
int f[101];
int t = 1;//time

int Depth(int n){
    if((f[n] != 0)){//既に探索が終了していたら、その節点は飛ばす
        return 0;
    }
    if(d[n] == 0){//はじめて通る節点だったら、dに時間を記録
        d[n] = t;
        t++;
    }
    if((A[n][0] != 0)){//隣接点が1つ以上ある場合は以下のループに入る
        for(int i=1; i<=A[n][0]; i++){
            //if(A[n][i] == n){//自分自身に返ってくるノードだったら、
            //    f[A[n][i]] = t;
            //    t++;
            //    return 0;
            //}
            if((A[n][i] != n) && (d[A[n][i]] == 0)){
                Depth(A[n][i]);
            }
        }
    }
    f[n] = t;
    t++;
}

int main(){
    int n, num;
    cin >> n;
    for(int k=1; k<=n; k++){
        d[k] = 0;
        f[k] = 0;
    }
    for(int i=1; i<=n; i++){
        cin >> num;
        cin >> A[i][0];
        for(int j=1; j<=A[i][0]; j++){
            cin >> A[i][j];
        }
    }

    for(int l=1; l<=n; l++){
        Depth(l);
        //cout << l << " " << d[l] << " " << f[l] << " " << endl;
    }
    for(int i=1; i<=n; i++){
        cout << i << " " << d[i] << " " << f[i] << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 2

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

int next(int u){//ntってなに？？現在地？
	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;
}