Go: package main

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

// repr state of visited node
// WHITE yet visit
// GEAY  visiting
// BLACK visited
const (
	WHITE int = iota
	GRAY
	BLACK
)

type dfsGraph struct {
	g      [][]int
	colors []int
	stime  []int // Start time of visiting node
	ftime  []int // Finish time of visiting node
}

var time int

func makeAdjList() [][]int {
	var n int
	fmt.Scanf("%d", &n)

	adj := make([][]int, n)
	for i := 0; i < n; i++ {
		adj[i] = make([]int, n)
	}

	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		sc.Scan()
		nodeInfo := strings.Split(sc.Text(), " ")
		outDegree, _ := strconv.Atoi(nodeInfo[1])

		if outDegree > 0 {
			for k := 0; k < outDegree; k++ {
				j, _ := strconv.Atoi(nodeInfo[k+2])
				j-- // convert 1 based to 0 based
				adj[i][j] = 1
			}
		}
	}

	return adj
}

func (dg dfsGraph) dfsVisit(u int) {
	// 頂点uを訪問中に設定
	dg.colors[u] = GRAY
	time++
	dg.stime[u] = time

	// uの隣接nodeを訪問
	for v := 0; v < len(dg.g); v++ {
		if dg.g[u][v] == 0 {
			continue // 辺がなければスキップ
		}

		// vが未訪問なら訪問
		if dg.colors[v] == WHITE {
			dg.dfsVisit(v)
		}
	}

	// 頂点uを訪問済みに設定
	dg.colors[u] = BLACK
	time++
	dg.ftime[u] = time
}

func (dg dfsGraph) dfs() {
	for i := 0; i < len(dg.g); i++ {
		if dg.colors[i] == WHITE {
			dg.dfsVisit(i)
		}
	}
}

func (dg dfsGraph) printDfsTime() {
	for i := 0; i < len(dg.g); i++ {
		fmt.Printf("%d %d %d\n", i+1, dg.stime[i], dg.ftime[i])
	}
}

func main() {
	adj := makeAdjList()
	colors := make([]int, len(adj))
	stime := make([]int, len(adj))
	ftime := make([]int, len(adj))
	graph := dfsGraph{adj, colors, stime, ftime}
	graph.dfs()
	graph.printDfsTime()
}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#include <stack>
using namespace std;
const int maxx = 110;
int n, m[maxx][maxx];
int u, num, v;
int d[maxx], f[maxx];
int flag[maxx];
int nowtime = 1;

void dfs(int u) {

	// ??\?????¶??´
	flag[u] = 1;
	d[u] = nowtime++;
	for (int i = 1; i <= n; i++) {
		if (flag[i] == 0 && m[u][i] == 1) {
			dfs(i);
		}
	}
	//????????¶??´
	f[u] = nowtime++;
}

int main()
{

	scanf("%d", &n);
	memset(m, 0, sizeof(m));
	memset(f, 0, sizeof(f));
	for (int i = 1; i <= n; i++) {
		scanf("%d %d", &u, &num);
		for (int j = 1; j <= num; j++) {
			scanf("%d", &v);
			m[u][v] = 1;
		}
	}
	
	dfs(1);
	for (int i = 1; i <= n; i++) {
		printf("%d %d %d\n", i, d[i], f[i]);
	}
	return 0;
}

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

int t = 0;

void dfs(vector<vector<int>> &adj_list, vector<vector<int>> &res, int u)
{
    res[u][0] = ++t;
    for (int i = 0; i < adj_list[u].size(); i++)
    {
        int v = adj_list[u][i];
        if (res[v][0] == 0)
        {
            dfs(adj_list, res, v);
        }
    }
    res[u][1] = ++t;
}

int main()
{
    int n;
    cin >> n;

    vector<vector<int>> adj_list(n);
    for (int i = 0; i < n; i++)
    {
        int id, k;
        cin >> id >> k;
        for (int j = 0; j < k; j++)
        {
            int u;
            cin >> u;
            adj_list[id - 1].push_back(u - 1);
        }
    }

    vector<vector<int>> res(n, vector<int>(2, 0));
    for (int i = 0; i < n; i++)
    {
        if (res[i][0] == 0)
        {
            dfs(adj_list, res, i);
        }
    }

    for (int i = 0; i < n; i++)
    {
        cout << i + 1 << " " << res[i][0] << " " << res[i][1] << endl;
    }

    return 0;
}

C++: #include<cstdio>
#include<stack>
using namespace std;
const char N_MAX = 105;
char n;
unsigned char time=0;
stack<int> sta;
bool matrix[N_MAX][N_MAX];
struct Node{
    //0:undiscovered 1:active 2:end
    char state;
    unsigned char stTime, endTime;
};
Node V[N_MAX];
void buildMatrix(){
	for(char i=0; i<n;i++){
		int degree, index;
		scanf("%u%u", &index, &degree);
		for(char j=0; j<degree; j++){
			int temp;
			scanf("%d", &temp);
			matrix[index-1][temp-1] = true;
		}
	}
}
char next(char num){
    for(char i=0;i<n;i++){
        if(matrix[num][i]&&V[i].state==0){
            return i;
        }
    }
    return -1;
}
void dfs() {
    for(char i = 0; i < n; i++) {
        if(V[i].state == 0) {
            sta.push(i);
            V[i].stTime = ++time;
            V[i].state = 1;
            while(!sta.empty()) {
                char active = sta.top();
                char nex = next(active);
                if(nex != -1) {
                    sta.push(nex);
                    V[nex].stTime = ++time;
                    V[nex].state = 1;
                } else {
                    sta.pop();
                    V[active].endTime = ++time;
                    V[active].state = 2;
                }
            }
        }
    }
}
int main(){
    scanf("%d", &n);
    buildMatrix();
    dfs();
    for(char i=0;i<n;i++){
        printf("%d %d %d\n", i+1, V[i].stTime, V[i].endTime);
    }
}