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+1)
	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++: //16D8103013E Sen Shunkou
#include<iostream>
int main(){
    int n;
    std::cin>>n;
    int A[n][n];
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            A[i][j]=0;
        }
    }
    int tmp,s,e;
    for(int i=0;i<n;i++){
        std::cin>>s;
        std::cin>>tmp;
        for(int j=0;j<tmp;j++){
            std::cin>>e;
            A[s-1][e-1]=1;
        }
    }

    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            if(j==0){
                std::cout<<A[i][j];
            }else std::cout<<" "<<A[i][j];
        }
        std::cout<<"\n";
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define ll long long
#define vvi vector<vector<int>>
#define vec vector
#define pq priority_queue
#define all(v) (v).begin(), (v).end()
#define uniqueV(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());
#define rep(i, n) for (int (i) = (0); (i) < (n); ++(i))
#define repp(i, m, n) for (int (i) = (m); (i) < (n); ++(i))
#define debug(x) cerr << #x << ": " << x << endl;
#define debug2(x, y) cerr<<"("<<#x<<", "<<#y<<") = "<<"("<<x<<", "<<y<<")"<<endl;
#define debug3(x, y, z) cerr<<"("<<#x<<", "<<#y<<", "<<#z<<") = "<<"("<<x<<", "<<y<<", "<<z<<")"<<endl;
#define debugB(x, y) cerr<<#x<<": "<<bitset<y>(x) << endl;
#define line() cerr << "---------------" << endl;

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

template<typename T>
void printA(vector<T> &printArray, char between = ' ') {
   int paSize = printArray.size();
   for (int i = 0; i < paSize; i++) { cerr << printArray[i] << between;}
   if (between != '\n') {cerr << endl;}
}

// ------------------------------------------------------------------------------------------
int N, turn;
int d[111], f[111];
vector<vector<int>> G;

void dfs(int from) {
   d[from] = ++turn;
   for (int to : G[from]) {
      if (!d[to]) dfs(to);
   }
   f[from] = ++turn;
}

int main() {
   // 入力
   cin >> N;
   G = vector<vector<int>>(N);
   rep (i, N) {
      int u, k;
      cin >> u >> k;
      u--;
      rep (j, k) {
         int a;
         cin >> a;
         a--;
         G[u].push_back(a);
      }
   }

   rep (i, N) {
      if (!d[i]) dfs(i);
   }

   rep (i, N) {
      printf("%d %d %d\n", i+1, d[i], f[i]);
   }

   return 0;
}

C++: #include <bits/stdc++.h>
#define pb push_back
using namespace std;

int num = 1;
bool visited[1000];
vector<int> v[1000], seq[1000];
void dfs(int k){
    seq[k].pb(num++);
    if(visited[k]) return;
    visited[k] = 1;
    for (auto t : v[k]){
        if(visited[t]) continue;
        dfs(t);
    }
    seq[k].pb(num++); return;

}
int main(){
    int n; cin >> n;
    memset(visited, 0, sizeof(visited));
    for (int i = 0; i < n; i++){
        int x, y, z; cin >> x >> y;
        for (int j = 0; j < y; j++){
            cin >> z; v[x].pb(z);
        }
    }
    for(int i = 1; i <= n; i++)
        sort(v[i].begin(), v[i].end());
    dfs(1);
    for (int i = 1; i <= n; i++){
        cout << i << ' ';
        for (auto k : seq[i])
        cout << k << ' ';
        cout << '\n';
    }
}

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

using namespace std;

struct Node {
    bool visit = false;
    vector<int> next;
    int position = 0;
    int start = 0;
    int end = 0;
};

int main() {
    int n, id, k, temp, time = 1;
    Node node[101];
    stack<int> st;

    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> id >> k;
        for (int j = 0; j < k; j++) {
            cin >> temp;
            node[id].next.push_back(temp);
        }
    }

    while (1) {
        int s = -1;
        for (int i = 1; i <= n; i++) {
            if (node[i].start == 0) {
                s = i;
                break;
            }
        }
        if (s == -1) {
            break;
        }
        
        node[s].start = time++;
        st.push(s);
        while (!st.empty()) {
            temp = st.top();
            if (node[temp].position < node[temp].next.size() && node[node[temp].next[node[temp].position]].visit == false) {
                node[node[temp].next[node[temp].position]].start = time++;
                st.push(node[temp].next[node[temp].position++]);
            }
            else {
                node[temp].visit = true;
                node[temp].end = time++;
                st.pop();
            }
        }
    }

    for (int i = 1; i <= n; i++) {
        cout << i << " " << node[i].start << " " << node[i].end << endl;
    }

    return 0;
}