Go: #include <bits/stdc++.h>
using namespace std;
static const int WHITE = 0;
static const int GRAY  = 1;
static const int BLACK = 2;
static const int N     = 100;

int n, tt;
vector<vector<int>> M(N, vector<int>(N));
vector<int> color(N), d(N), f(N);

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

void dfs() {
  tt = 0;

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

int main() {
  int u, v, k;
  cin >> n;
  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();
}

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

using namespace std;

int N;
vector<vector<int>> tree;
vector<pair<int,int>> times;

void stamp(int ind, int &time){
	//cout << ind << "," << time << endl;
	if(times[ind].first == 0) times[ind].first = time++;
	else return;
	if(tree[ind].size() == 0){
		times[ind].second = time++;
		//cout<<"break! " << ind << endl;
		return;
	}
	for(int i=0;i<tree[ind].size();i++){
		//cout << tree[ind][i] << endl;
		stamp(tree[ind][i],time);
	}
	//cout << ind << ":" << time << endl;
	times[ind].second = time++;
}

int main(){
	cin >> N;
	tree = vector<vector<int>>(N+1);
	times = vector<pair<int,int>>(N+1,make_pair(0,0));

	for(int i=1;i<N+1;i++){
		int ind, branch;
		cin >> ind >> branch;
		vector<int> tmp(branch);
		for(int j=0;j<branch;j++){
			int in;
			cin >> in;
			tmp[j] =  in;
		}
		tree[ind] = tmp;
	}

	int time = 1;
	stamp(1,time);

	int i = 1;
	for(auto st:times){
		if(i<=N)
			cout << i << " " << times[i].first << " " << times[i].second << endl;
		i++;
	}

	return 0;
}

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

#include<iostream>

#define MAX 100
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 <cstdio>
#include <cstring>
#include <stack>
#define N 110
using namespace std;
stack<int> s;
int n;
int m[N][N];
int used[N];
int time = 1;
int bb_start[N];
int bb_end[N];
int getnext(int u){
    for(int i = 1; i <= n; i++){
        if(m[u][i] == 1 && used[i] == 0) return i;
    }
    return -1;
}
void dfs(int root){
    used[root] = 1;
    bb_start[root] = time++;

    while(!s.empty()) s.pop();
    s.push(root);
    while(!s.empty()){
        int u = s.top();
        int v = getnext(u);
        if(v != -1 && used[v] == 0){
            used[v] = 1;
            bb_start[v] = time++;
            s.push(v);
        } else{
            bb_end[u] = time++;
            s.pop();
        }
    }
}
int main(){
    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++) used[i] = 0;
    scanf("%d", &n);
    for(int p = 0; p < n; p++){
        int node, k;
        scanf("%d %d", &node, &k);
        for(int i = 0; i < k; i++){
            int b;
            scanf("%d", &b);
            m[node][b] = 1;
        }
    }
    for(int i = 1; i <= n; i++) if(used[i] == 0) dfs(i);
    for(int i = 1; i <= n; i++){
        printf("%d %d %d\n", i, bb_start[i], bb_end[i]);
    }
    return 0;
}

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

int n, dd[101], f[101], tmap[101][101];
int color[101], t = 1;
stack<int> S;

int a(){
	int d = S.top();
	dd[d] = t;
	t++;
	color[d] = 1;
	for (int i = 1; i <= n; i++){
		if (color[i] == 0 && tmap[d][i] == 1){
			S.push(i);
			a();
		}
	}
	
	f[d] = t;
	t++;
	return 0;
}


int main(){
	cin >> n;
	for (int i = 0; i < 100; i++){
		dd[i] = f[i] = color[i] = 0;
		for (int j = 0; j < 100; j++){
			tmap[i][j] = 0;
		}
	}

	int u, k, v;

	for (int i = 0; i < n; i++){
		cin >> u >> k;
		for (int j = 0; j < k; j++){
			cin >> v;
			tmap[u][v] = 1;
		}
	}
	for (int i = 1; i <= n; i++){
		if (color[i] == 0){
			S.push(i);
			a();
		}
	}
	for (int i = 1; i <= n; i++){
		cout << i << " " << dd[i] << " " << f[i] << endl;
	}
	return 0;
}

C++: #include<iostream>
#include<climits>
#include<vector>
#include<list>
#include<functional>
#include<algorithm>
#include<string>
#include<cmath>
#include<complex>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<deque>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) for(int i=0;i<(n);i++)
#define INF (int)1e9
#define INFL (ll)1e11
using namespace std;
typedef long long ll;
typedef pair<int, int> P;

vector<int> d(100, 1), f(100);

int dfs(vector<vector<int>> a, int s) {
	int n = a.size();
	int res = 0;
	REP(j, n) {
		if (d[j] == 1 && a[s][j]) {
			if (res == 0) {
				d[j] = d[s] + 1;
			}
			else {
				d[j] = res;
			}
			res = dfs(a, j) + 1;
		}
	}
	if (res == 0) return f[s] = d[s] + 1;
	return f[s] = res;
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n;
	cin >> n;
	vector<vector<int>> a(n, vector<int>(n, 0));
	REP(i, n) {
		int u, k;
		cin >> u >> k;
		u--;
		REP(j, k) {
			int v;
			cin >> v;
			a[u][--v] = 1;
		}
	}
	dfs(a, 0);
	REP(i, n) {
		cout << i + 1 << " " << d[i] << " " << f[i] << "\n";
	}
	
	return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;
#define rep(i, n) for(int i=0;i<(n);i++)
const int INF = 1001001001;
int n, u, k;
int D[100],F[100];
vector<int> edges[100];
int tim = 0;

void dfs(int cur) {
	if (D[cur] == INF) {
		tim += 1;
		D[cur] = tim;//タイムスタンプ押印
	}	
	for (int dst = 0; dst < n; dst++) {
		vector<int>::iterator result = find(edges[cur].begin(), edges[cur].end(), dst);
		if (result != edges[cur].end() && D[dst] == INF) dfs(dst);
	}
	tim += 1;
	F[cur] = tim;
		 //タイムスタンプ押印		
}

int main() {
	cin >> n; //n頂点


	for (int i = 0; i < n; i++)//iは頂点
	{
		cin >> u >> k;
		for (int j = 0; j < k; j++)
		{
			int l;
			cin >> l;
			edges[u - 1].push_back(l - 1);
		}//入力終わり
		D[i] = INF;
		F[i] = INF;		
	}
	for (int p = 0; p < n; p++) {
		if(D[p]==INF)dfs(p);//未訪問ならばッてこと
	}
	
	for (int i = 0; i < n; i++) {
		cout << i + 1 << " " << D[i] <<" "<<F[i]<< endl;		
	}
	return 0;
}

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

typedef struct {
	bool endflag;
	int firsttime;
	int endtime;
}State;

const int Max = 100;
int map[Max + 1][Max + 1] = { 0 };
std::stack<int> st;
std::vector<State> state;


int main()
{
	int n, k, v, x;
	int cnt = 1;

	std::cin >> n;
	for (int i = 1; i <= n; i++) {
		std::cin >> x >> k;
		for (int j = 1; j <= k; j++) {
			std::cin >> v;
			map[x][v] = 1;
		}
	}

	State s = { false,0,0 };
	for (int i = 0; i <= n; i++) {
		state.push_back(s);
	}

	while (1) {
		if (st.empty() == true) {
			if (state[1].endflag == true) {
				break;
			}
			else {
				st.push(1);
				state[1].firsttime = cnt;
				cnt++;
				continue;
			}
		}

		bool flag = false;
		for (int i = 1; i <= n; i++) {
			if (map[st.top()][i] == 1) {
				if (state[i].endflag == false) {
					st.push(i);
					state[i].firsttime = cnt;
					cnt++;
					flag = true;
					break;
				}
			}
		}
		if (flag == true) {
			continue;
		}
		else {
			state[st.top()].endflag = true;
			state[st.top()].endtime = cnt;
			cnt++;
			st.pop();
		}
	}

	for (int i = 1; i <= n; i++) {
		std::cout << i << " " << state[i].firsttime << " " << state[i].endtime << std::endl;
	}

	return 0;
}