Go: package main

/*
グラフの表現 隣接行列による表現
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		g[i] = make([]int, n+1)
		ints := eGetInts(scanner)
		num := ints[0]
		for j := 0; j < ints[1]; j++ {
			g[num][ints[j+2]] = 1
		}
	}
	dist := make([]int, n+1)
	for i := 0; i < len(dist); i++ {
		dist[i] = -1
	}
	q := []int{}

	// 訪問する
	q = append(q, 1)
	dist[1] = 0

	// キューが空でない限り
	for len(q) > 0 {
		// 先頭を取り出す
		top := 0
		top, q = q[0], q[1:]
		// 隣接マスを入れる.
		for i := 1; i < n+1; i++ {
			// 辺がある
			if g[top][i] == 1 {
				if dist[i] == -1 {
					// 訪問済みでなければ
					q = append(q, i)
					dist[i] = dist[top] + 1
				}
			}
		}
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, dist[i])
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

C++: #include <stdio.h>
#include <iostream>
using namespace std;

class Adjl{
private:
	int u;
	int k;
	Adjl **next;
	int check_id;
public:
	Adjl(int u);
	~Adjl(){ if (next != NULL) delete[] next; }
	void setV(int k, Adjl *vk);
	int breadthFirstSearch(int id);
	void print(int id);
};

Adjl::Adjl(int u)
{
	this->u = u;
	k = 0;
	next = NULL;
	check_id = 0;
}

void Adjl::setV(int k, Adjl *vk)
{
	if (this->k == 0) next = new Adjl*[k];
	next[this->k] = vk;
	(this->k)++;
}

int Adjl::breadthFirstSearch(int id)
{
	if (id == check_id) return -1;
	else check_id = id;

	if (id == u) {
		return 0;
	}

	for (int i = 0; i < k; i++) {
		if (id == next[i]->u) {
			return 1;
		}
	}
	int d_min = -1;
	for (int i = 0; i < k; i++) {
		int d = next[i]->breadthFirstSearch(id);
		if (d == -1) continue;
		if (d_min == -1) d_min = d + 1;
		else d_min = min(d_min, d + 1);
	}
	return d_min;
}

void Adjl::print(int id)
{
	cout << id << " " << breadthFirstSearch(id) << endl;
}

int main(void)
{
	int n;
	cin >> n;
	
	Adjl **adjl = new Adjl*[n];
	int check[100] = {0};

	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		if (check[i] == 0) {
			adjl[i] = new Adjl(u);
			check[i] = 1;
		}
		check[i] = 1;
		for (int j = 0; j < k; j++) {
			int vk;
			cin >> vk;
			if (check[vk - 1] == 0) {
				adjl[vk - 1] = new Adjl(vk);
				check[vk - 1] = 1;
			}
			adjl[i]->setV(k, adjl[vk - 1]);
		}
	}

	for (int i = 1; i <= n; i++) {
		adjl[0]->print(i);
	}

	delete[] adjl;
	return 0;
}

C++: #include <iostream>
#include <queue>
using namespace std;
typedef long long ll;
#define int ll

int g[105][105], d[105], n;

void bfs() {
  queue<int> q;
  q.push(0);
  fill(d, d + n, -1);
  d[0] = 0; 

  while(!q.empty()) {
    int que = q.front();
    q.pop();
    for (int i = 0; i < n; i++) {
      if (g[que][i] && d[i] == -1) {
        d[i] = d[que] + 1;
        q.push(i);
      }
    }
  }
}

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

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

C++: #include<iostream>
#include<algorithm>
#include<queue>
#define MAX 101
using namespace std;
int n,d[MAX],color[MAX],A[MAX][MAX];
queue<int> Number_of_vertices;
void input(void){
    cin >> n;
    for(int i=0;i<n;i++){
        d[i] = -1;
        color[i] = 0;
        A[i][i] = 0;
    }
    for(int i=0;i<n;i++){
        int id,adj;
        cin >> id >> adj;
        id--;
        if(i==0){
            Number_of_vertices.push(id);
            d[id] = 0;
            color[id] = 1;
        }
        for(int j=0;j<adj;j++){
            int k;
            cin >> k;
            A[id][--k] = 1;
        }
    }
}
void Breadth_First_Search(void){
    while(!Number_of_vertices.empty()){
        int u = Number_of_vertices.front();
        Number_of_vertices.pop();
        for(int i=0;i<n;i++){
            if(color[i]==0 && A[u][i]==1){
                d[i] = d[u] + 1;
                color[i] = 1;
                Number_of_vertices.push(i);
            }
        }
    }
}
void print(void){
    for(int i=0;i<n;i++){
        cout << i + 1 << ' ' << d[i] << endl;
    }
}
int main(void){
    input();
    Breadth_First_Search();
    print();
    return 0;
}

C++: #include<stdio.h>
#define N 101
#define WHITE 2
#define GRAY 1
#define BLACK 0
#define INF 1000000

 
int n, h= 0, t = 0;
int col[N], d[N], a[N][N], e[N]; 

int Que[N];



 int Dequeque(){
  h++;
  return Que[h - 1];
}
void Enqueque(int b){
  Que[t] = b;
  t++;
}
 
void BFS(int s){
  int i, u, next;
  for(i = 1; i < n+1; i++){
      col[i] = WHITE;


      d[i] = -1;
  }
 
  col[s] = GRAY;
  d[s] = 0;
  Enqueque(s);
 
  while(h != t){
    u = Dequeque();
    for(i = 1; i <= n; i++){
      if((col[i] == WHITE) && (a[u][i] == 1)){


    col[i] = GRAY;
    d[i] = d[u] + 1;
    Enqueque(i);
      }
    }
   

    col[u] = BLACK;
  }
}
 

  
main(){
 
  scanf("%d", &n);
 
  int i, u, j,y=1;



  /*配列の初期化*/
  for(i = 1; i < n+1; i++){
    for(j = 1; j < n+1; j++){
     

 a[i][j] = 0;

    }
  }

  int x; 
  for(i = 1; i < n+1; i++){
    scanf("%d%d", &u, &e);
    for(j = 1; j <= e; j++){
      scanf("%d", &x);
      a[i][x] = 1;
    }
  }
 
  BFS(y);
   
  for(i = 1; i < n+1; i++){
    printf("%d ", i);
    printf("%d\n", d[i]);
  }
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
#define all(x) (x).begin(),(x).end()
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
typedef long long ll;
const long long INF = 1e9;
typedef pair<int, int> P;
int main()
{
    int N;
    cin >> N;
    vector<vector<int>> G(N);
    rep(i, N) {
        int u, k;
        cin >> u >> k;
        rep(j, k) {
            int v;
            cin >> v;
            G[u - 1].push_back(v - 1);
        }
    }

    vector<int> d(N, INF);
    d[0] = 0;
    queue<int> que;
    que.push(0);
    while (!que.empty()) {
        int v = que.front(); que.pop();
        for (auto to : G[v]) {
            if (d[to] != INF) continue;
            d[to] = d[v] + 1;
            que.push(to);
        }
    }

    rep(i, N) {
        cout << i + 1 << " " << (d[i] == INF ? -1 : d[i]) << endl;
    }
    return 0;
}