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 <stdio.h>
#include <iostream>
#include <stack>
#include <string>
using namespace std;

#define NUM 100
int node_num;
int V[NUM + 1][NUM + 1];
int d[NUM + 1];
int f[NUM + 1];
string color[NUM + 1];
int t;
int pos;
stack<int> s;

void createAdj(int n){
    for(int j = 0; j <= n; j++){
        if(j == 0){
            V[0][j] = 0;
        }
        V[0][j] = 1;
    }

    for(int i = 1; i < NUM; i++){
        for(int j = 1; j < NUM; j++){
            V[i][j] = 0;
        }
    }

    for(int i = 0; i < n; i++){
        int num1;
        scanf("%d", &num1);

        int n;
        scanf("%d", &n);

        int num2;
        for(int j = 0; j < n; j++){
            scanf("%d", &num2);
            V[num1][num2] = 1;
        }
    }
}

int search(int n){
    for(int i = 1; i <= node_num; i++) {
        if(V[n][i] == 1 && color[i] == "white")
            return i;
    }
    return -1;
}

void dfs_init(){
    t = 0;
    for(int i = 0; i < NUM; i++){
        color[i] = "white";
    }
}

void dfs(){
    s.push(0);
    pos = 0;
    color[0] = "grey";
    d[0] = t;

    while(s.size()){
        int u = s.top();
        int next_node = search(u);
        if(next_node != -1){
            pos = next_node;
            s.push(next_node);
            pos = next_node;
            t++;
            color[next_node] = "grey";
            d[next_node] = t;
        }else{
            s.pop();
            color[u] = "black";
            t++;
            f[u] = t;
        }
    }
}

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

int main(void){
    scanf("%d", &node_num);
    createAdj(node_num);

    dfs_init();
    dfs();

    print();
}

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

bool A[110][110];
int flag[110],in[110],out[110];
int now=1,n;

void dfs(int u){
	flag[u]=1;
	in[u]=now++;
	for(int i=1;i<=n;i++){
		if(flag[i]==0 && A[i][u]==true){
			dfs(i);
		}
	}
	out[u]=now++;
	return ;
}

int main(){
	int a,b,c;
	cin>>n;
	for(int i=1;i<=n;i++){
			for(int j=1;j<=n;j++){
				A[i][j]=false;
		}
	}
	for(int i=1;i<=n;i++){
		cin>>a>>b;
		for(int j=1;j<=b;j++){
			cin>>c;
			A[a][c]=true;
			A[c][a]=true;
		}
	}
	for(int i=1;i<=n;i++){
		if(flag[i]==0) dfs(i);
	}
	for(int i=1;i<=n;i++){
		cout<<i<<" "<<in[i]<<" "<<out[i]<<endl;
	}
	return 0;
}

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

using namespace std;
int d[101];
int f[101];
int n;
int M[101][101];
int t;
void DFS(int v) {
	t = t + 1;
	d[v] = t;
	for (int j = 1; j < n + 1; j++) {
		if (M[v][j] == 1) {
			if (d[j] == 0) {
				DFS(j);

			}
		}
	}
	t = t + 1;
	f[v] = t;

}

int main() {
	int  u, k, v;//頂点数、頂点の番号、出次数、隣接する頂点の番号
	t = 0;

	cin >> n;



	//初期化
	for (int i = 0; i < 101; i++) {
		d[i] = 0;
		f[i] = 0;
		for (int j = 0; j < 101; j++) {
			M[i][j] = 0;

		}
	}

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


	
	for (int i = 1; i < n + 1; i++) {
		if (d[i] == 0) {
			DFS(i);
		}
	}
	
	for (int i = 1; i < n + 1; i++) {
		cout << i << " " << d[i] << " " << f[i] << endl;
	}

	return 0;
}

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

using namespace std;
static const int MAX=101;
bool Visited[MAX]; //??\?????????????¢??????????
vector<int> Adjacency[MAX];
int dTime[MAX]; int fTime[MAX]; //?¢??????°??¶??´????¢?????????¶??´
void dfs(int i,int& clock) //??¶????????°?????\???????????¨
{
    clock++;
    Visited[i]=true;
    dTime[i]=clock; //???????????°??¶??´
    for(int j=0;j<Adjacency[i].size();j++)
    {
        if(Visited[Adjacency[i][j]]==true) continue;
        dfs(Adjacency[i][j],clock);
    }
    clock++; //???????????????????¢????
    fTime[i]=clock;
}

int main()
{
    int n;
    cin>>n;
    for(int i=1;i<=n;i++) Visited[i]=false;

    for(int i=1;i<=n;i++)
    {
        int p;cin>>p;
        int num;
        cin>>num;

        for(int j=0;j<num;j++)
        {
            int t;
            cin>>t;
            Adjacency[p].push_back(t);
        }
    }
    int clock=0;
    dfs(1,clock);
    for(int i=1;i<=n;i++)
        cout<<i<<' '<<dTime[i]<<' '<<fTime[i]<<endl;
}

C++: #include<iostream>

int d[101]={0};
int f[101]={0};
int us[101]={0};
int V[101][101]={0};
int t=1;
int n;

void tansaku(int x)
{
  d[x]=t++;
  us[x]++;
  for(int i=0;i<n;i++){
    if(V[x][i]==1 and us[i]==0){
      tansaku(i);
    }
  }
  f[x]=t++;
}


int main()
{
  int n;
  int u,k,v;
  std::cin>>n;
  for(int i=0;i<n;i++){
    std::cin>>u>>k;
    for(int j=0;j<k;j++){
      std::cin>>v;
      V[u-1][v-1]=1;
    }
  }
  for(int i=0;i<n;i++){
    if(us[i]==0){
      tansaku(i);
    }
  }
  for(int i=0;i<n;i++){
    std::cout<<i+1<<" "<<d[i]<<" "<<f[i]<<"\n";
  }
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define REP(i,n) for(int i=0; i<(n); i++)
#define REP2(i,x,n) for(int i=x; i<(n); i++)
#define PRINT(x) cout<<(x)<<endl
#define INF 1000000000000 // 10^12
#define MOD 1000000007 // 10^9+7
#define PB push_back
#define MP make_pair

const int MAX_N = 100, MAX_K = 100;

int n, u, k, v[MAX_K];

vector<int> G[MAX_N];
int d[MAX_N], f[MAX_N];
int t = 0;

void dfs(int);

int main() {
    // input
    cin >> n;
    REP(i, n) {
        cin >> u >> k;
        u--;
        REP(j, k) {
            cin >> v[j];
            v[j]--;
            G[u].PB(v[j]);
        }
    }

    // init d
    REP(i, n) d[i] = -1;

    // dfs
    REP(i, n) {
        if (d[i] == -1) dfs(i);
    }

    // output
    REP(i, n) {
        int id = i + 1;
        printf("%d %d %d\n", id, d[i], f[i]);
    }

    return 0;
}

void dfs(int pos) {
    d[pos] = ++t;
    REP(i, G[pos].size()) {
        int to = G[pos][i];
        if (d[to] != -1) continue;
        dfs(to);
    }
    f[pos] = ++t;
    return;
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define loop(i,a,b) for(i=a;i<b;i++)
#define rloop(i,a,b) for(i=a;i>=b;i--)
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
const int inf=1000000001;
const ll INF=1e16;
#define MOD 1000000007
#define mod 1000000009
#define pi 3.14159265358979323846
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;
static const int N=101;

int n,tt=0;
vii M(N,vi(N,0));
vi color(N,WHITE),d(N),f(N),nt(N,0);

void dfs();
void dfs_visit(int);
int next(int);

int main(){
	int i,j,u,k,v;
	cin>>n;
	loop(i,0,n){
		cin>>u>>k;
		loop(j,0,k){
			cin>>v;
			M[u][v]=1;
		}
	}
	dfs();
}

void dfs(){
	int i;
	loop(i,1,n+1){
		if(color[i]==WHITE){
			dfs_visit(i);
		}
	}
	loop(i,1,n+1){
		cout<<i<<" "<<d[i]<<" "<<f[i]<<endl;
	}
}

void dfs_visit(int r){
	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;
		}
	}
}

int next(int u){
	int v;
	loop(v,nt[u]+1,n+1){
		nt[u]=v;
		if(M[u][v]){
			return v;
		}
	}
	return -1;
}