Go: package main

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

type TimeRecord struct {
	discoverTime int
	finishTime   int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	timeRecordMap := make([]TimeRecord, n)
	childrenMap := make([][]int, n)
	for i := 1; i <= n; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		timeRecordMap[node-1] = TimeRecord{-1, -1}

		childNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		childrenMap[node-1] = make([]int, childNum)
		for j := 0; j < childNum; j++ {
			child, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			childrenMap[node-1][j] = child
		}
	}

	// TODO: always start with 1?
	timer := 1
	visit(1, &timer, childrenMap, timeRecordMap)
	for k, v := range timeRecordMap {
		fmt.Printf("%d %d %d\n", k+1, v.discoverTime, v.finishTime)
	}
}

func visit(currentNode int, timer *int, childrenMap [][]int, timeRecordMap []TimeRecord) {
	if timeRecordMap[currentNode-1].discoverTime > 0 {
		return
	}
	children := childrenMap[currentNode-1]
	timeRecordMap[currentNode-1] = TimeRecord{*timer, timeRecordMap[currentNode-1].finishTime}
	(*timer)++
	for i := 0; i < len(children); i++ {
		visit(children[i], timer, childrenMap, timeRecordMap)
	}
	timeRecordMap[currentNode-1] = TimeRecord{timeRecordMap[currentNode-1].discoverTime, *timer}
	(*timer)++
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

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

struct time_check {
    int find_time, end_time;
};

int main() {
    int G[101][101] = {0};
    time_check t[101];

    for (int i = 1; i <= 100; i++) t[i].end_time = 0;

    stack<int> S;
    int n, u, v, k, elapsed=1;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            cin >> v;
            G[u][v] = 1;
        }
    }
    S.push(1);
    t[1].find_time = 1;
    while (! S.empty()) {
        elapsed++;
        u = S.top();
        for (int i = 1; i <= n + 1; i++) {
            if (G[u][i] == 1 && t[i].end_time == 0) {
                t[i].find_time = elapsed;
                G[u][i] = 0;
                S.push(i);
                break;
            }
            if (i == n + 1) {
                t[u].end_time = elapsed;
                S.pop();
            }
        }
    }

    for (int i = 1; i <= n; i++) {
        cout << i << " " << t[i].find_time << " " << t[i].end_time << endl;
    }

    return 0;
}
このコードはWrong Answerです...
理由は以下のコードのl.111のとこのように未訪問の頂点を始点としてdfsしてないから
*/

#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 BRACK = 2;

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

// uに隣接するvを番号順に取得
int next(int u) {
    for (int v = nt[u]; v < n; v++) {
        nt[u] = v + 1;
        if (M[u][v]) return v;
    }
    return -1;
}

// スタックを用いた深さ優先探索
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] = BRACK;
            f[u] = ++tt;
        }
    }
}

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

    // 未訪問のuを始点として深さ優先探索
    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<bits/stdc++.h>
using namespace std;

int adj[101][101],d[101],f[101], n;

int step;
void dfs(int start){
	stack<int> S;
	S.push(start);

	++step;
	d[start]=step;

	while(S.size()){
		int u=S.top();

		int v=0;
		for(int i=1;i<=n;i++){
			if(adj[u][i]==1 && d[i]==0){
				v=i;	break;
			}
		}

		++step;
		if(v==0){
			f[u]=step;
			S.pop();
		}else{
			d[v]=step;
			S.push(v);
		}
	}
}

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

	step=0;
	for(int i=1;i<=n;i++){
		if(d[i]==0)dfs(i);
	}

	for(int i=1;i<=n;i++){
		printf("%d %d %d\n",i,d[i],f[i]);
	}

	return 0;
}

C++: /**
 * Depth first search.
 * start from node 1
 * 1) increment time 
 * 2) find non visited adjacent node
 * 3) if found move to that node.  d[v'] = time
 * 4) if not found. f[v] = time
 * 5) else end.
 * 5) go to 2.
 */

#include <iostream>
using namespace std;
const int N = 101;
int adj[N][N] = {0};
int d[N]={0};
int f[N]={0};
int t = 1;

void dfs(int n) {
	d[n]=t;
	int k = adj[n][0];
	for (int j=1;j<=k;j++) {
		int nn = adj[n][j];
		if (d[nn]) continue;
		t++;
		dfs(nn);
	}
	f[n]=++t;
}

int main()
{
	int n;
	cin >> n;
	for (int i=1;i<=n;i++){
		int j, k;
		cin >> j >> k;
		adj[j][0]=k;
		for (int m=1;m<=k;m++) {
			int a;
			cin >> a;
			adj[j][m]=a;
		}
	}
	dfs(1);

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

	return 0;
}

C++: #include<stdio.h>
#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;

void visit(int);
void dfs(void);

int main(){
  int u,v,k,i,j;

  scanf("%d",&n);
  for(i=0;i<n;i++){
    for(j=0;j<n;j++)M[i][j]=0;
  }

  for(i=0;i<n;i++){
    scanf("%d %d",&u,&k);
    u--;
    for(j=0;j<k;j++){
      scanf("%d",&v);
      v--;
      M[u][v]=1;
    }
  }

  dfs();

  return 0;
}

void visit(int u){
  int v;
  color[u]=GRAY;
  d[u]=++tt;
  for(v=0;v<n;v++){
    if(M[u][v]==0)continue;
    if(color[v]==WHITE){
      visit(v);
    }
  }
  color[u]=BLACK;
  f[u]=++tt;
}

void dfs(){
  int u;
  for(u=0;u<n;u++)color[u]=WHITE;
  tt=0;
  for(u=0;u<n;u++){
    if(color[u]==WHITE)visit(u);
  }
  for(u=0;u<n;u++){
    printf("%d %d %d\n",u+1,d[u],f[u]);
  }
}

C++: #include<iostream>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
using namespace std;
int G[100][100] = {};
int time = 0;
typedef struct ANS
{
	int id, t, e;
	bool done;
};

void rec(ANS a[],int t)
{
	time++;
	a[t].t = time;
	a[t].done = true;
	FOR(i, 0, 100)
	{
		if (G[t][i] == 1 && a[i].done == false)
		{
			rec(a, i);
		}
	}
	time++;
	a[t].e = time;
}

int main()
{
	ANS ans[101];
	int n;
	cin >> n;
	FOR(i, 0, n)
	{
		ans[i].id = i + 1;
		ans[i].done = false;
		int u, m;
		cin >> u >> m;
		FOR(j, 0, m)
		{
			int l;
			cin >> l;
			G[u - 1][l - 1] = 1;
		}
	}
	rec(ans, 0);
	FOR(i, 0, n)
	{
		cout << ans[i].id << " " << ans[i].t << " " << ans[i].e << endl;
	}
	return 0;
}

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

int r[101][101];
int d[101], f[101], num, visit[100]={0}, p=1;

void dfs(int n){
    if(visit[n]!=1){
        visit[n] = 1;
        d[n] = p++;
        for(int i=1; i<=num; i++)
            if(r[n][i]) dfs(i);
        f[n] = p++;
    }
}

int main(void){
    int u, k, v;
    cin >> num;
    for(int i=1; i<=num; i++){
        cin >> u >> k;
        for(int j=1; j<=k; j++){
            cin >> v;
            r[u][v]=1;
        }
    }
    for(int i=1; i<=num; i++){
        if(visit[i]!=1) dfs(i);
    }
    for(int i=1; i<=num; i++)
        cout << i << " " << d[i] << " " << f[i] << endl;
    return 0;
}