Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Queue struct {
	arr []int
}

func (q *Queue) push(v int) {
	q.arr = append(q.arr, v)
}

func (q *Queue) pop() int {
	res := q.arr[0]
	q.arr = q.arr[1:]
	return res
}

func (q *Queue) isEmpty() bool {
	return len(q.arr) == 0
}

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	var q Queue
	seen := make([]int, N)
	for i := 0; i < N; i++ {
		seen[i] = -1
	}
	var search func(cur int)
	search = func(cur int) {
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if seen[next] == -1 {
				q.push(next)
				seen[next] = seen[cur] + 1
			}
		}
	}
	q.push(0)
	seen[0] = 0
	for !q.isEmpty() {
		search(q.pop())
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i+1, seen[i])
	}
	wtr.Flush()
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n) ; i++)
constexpr auto INF = 2147483647;
typedef long long ll;

int main(){

  int n;
  cin >> n;
  int score[101];
  bool adjacent_graph[101][101];
  rep(i,101){
    score[i] = -1;
    rep(j,101) adjacent_graph[i][j] = false;
    }

  int vertex,edge,direction;
  rep(i,n){
    cin >> vertex >> edge;
    rep(j,edge){
      cin >> direction;
      adjacent_graph[vertex][direction]  = true;
      // adjacent_graph[direction][vertex]  = true;
    }
  }
  queue<int> que;
  que.push(1);
  score[1] = 0;
  while(!que.empty()){
    int now = que.front();que.pop();
    rep(i,n+1) {
      if(adjacent_graph[now][i] && score[i] == -1){
        score[i] = score[now]+1;
        que.emplace(i);
      }
    }
  }

  rep(i,n) cout  << i+1 << " " << score[i+1] << endl;

  return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;
const int MAXN = 105;
const int INF = 1<<21;
int a[105][105];
int d[MAXN];
int n;


void bfs(int s)
{
	for(int i = 0; i < n; i++)
	{
		d[i] = INF;
	}
	queue<int> q;
	q.push(s);
	d[s] = 0;
	
	int u;
	while(!q.empty())
	{
		u = q.front(); q.pop();
		for(int v = 0; v < n; v++)
		{
			if(d[v] != INF)
				continue;
			if(a[u][v] == 0)
				continue;
			d[v] = d[u] + 1;
			q.push(v);
		}
	}
	
	for(int i = 0; i < n; i++)
	{
		if(d[i] != INF)
			cout << i+1 << " " << d[i] << endl;
		else
			cout << i+1 << " " << -1 << endl;
	}
}

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--;
			a[u][v] = 1;
		}
	}
	bfs(0);
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
static const int INF=1000000;

int main(){
  int n,u,k,v;
  cin>>n;
  vector<int> G[n];
  int D[n];
  
  for(int i=0;i<n;i++){
    cin>>u>>k;
    u--;
    for(int j=0;j<k;j++){
      cin>>v;
      v--;
      G[u].push_back(v);
      //cout<<"#"<<u<<v<<endl;
      //G[v].push_back(u);
    }
  }
  for(int i=0;i<n;i++){
    D[i]=INF;
  }
    
  D[0]=0;
  queue<int>Q;
  Q.push(0);
  while(!Q.empty()){
    int u=Q.front();Q.pop();
    for(int i=0;i<G[u].size();i++){
      v=G[u][i];
      if(D[v]!=INF) continue;
      D[v]=D[u]+1;
      Q.push(v);
    }
  }
  for(int i=0;i<n;i++){
    cout<<i+1<<" "<<(D[i]==INF ? -1:D[i])<<endl;
  }
  
  return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;
static const int N = 100;
static const int INFTY = (1<<21);

int n, M[N][N];
int d[N];
void bfs(int s){
    queue<int> q;
    q.push(s);
    for ( int i = 0; i < n; i++ ) d[i] = INFTY;
    d[s] = 0;
    int u;
    while ( !q.empty() ){
        u = q.front(); q.pop();
        for ( int v = 0; v < n; v++ ){
            if ( M[u][v] == 0) continue;
            if ( d[v] != INFTY) continue;
            d[v] = d[u] + 1;
            q.push(v);
            
        }
    }
    for ( int i = 0; i < n; i++ ) {
        cout << i+1 << " " << ( (d[i] == INFTY) ? (-1) : d[i] ) << endl;
    }
}
int main() {
    int u, k,v;
    
    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;
        }
    }
    bfs(0);
    
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define MAX 105

vector<vector<int> > vec;
vector<int> ve;
int dis[MAX];
queue<int> Q;
int n;

int search(int start, int end) {
	while(!Q.empty()) Q.pop();
	Q.push(start);
	for (int i = 1; i <= n; i++) {
		dis[i] = 0;
	}
	int now, len = 0;
	while (!Q.empty()) {
		now = Q.front();
		Q.pop();
		if (now == end)
			return dis[now];
		if (dis[now] == len)
			len++;
		for (int cnt = 1; cnt <= vec[now][0]; cnt++) {
			if (dis[vec[now][cnt]] == 0) {
				dis[vec[now][cnt]] = len;
				Q.push(vec[now][cnt]);
			}
		}
	}
	return -1;
}

int main(void) {
	vec.push_back(ve);
	int u, k, v, i;
	cin >> n;
	for (i = 1; i <= n; i++) {
		ve.clear();
		cin >> u >> k;
		ve.push_back(k);
		while (k--) {
			cin >> v;
			ve.push_back(v);
		}
		vec.push_back(ve);
	}

	for (i = 1; i <= n; i++) {
		cout << i << " " << search(1, i) << endl;
	}
	
}

C++: #include<iostream>
#include<queue>
using namespace std;
static const int N = 100;
static const int INFTY = (1 << 21);

int n, M[N][N], d[N];

void bfs(int s) {
	queue<int> q;
	q.push(s);
	for(int i =0; i < n; i++) {
		d[i] = INFTY;
	}
	d[s] = 0;
	int u;
	while(!q.empty()) {
		u = q.front();
		q.pop();
    	for(int v = 0; v < n; v++) {
		    if(M[u][v] == 0) continue;
			if(d[v] != INFTY) continue;
			d[v] = d[u] + 1;
			q.push(v);
			} 
	}
	for(int i = 0; i < n; i++) {
		cout << i + 1 << " " << ( (d[i] == INFTY) ? (-1) : d[i] ) << endl;
	} 	
}

int main() {
	int v, k ,u;
	cin >> n;
	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++) {
		cin >> u >> k;
		for(int j = 0; j < k; j++) {
			cin >> v;
			M[u-1][v-1] = 1;
		}
	}
	
	bfs(0);
	
	return 0;
	
}