Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	visitedAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		visitedAt: -1,
		adjs: adjs,
	}
}

func (v *vertex) isVisited() bool {
	return v.visitedAt >= 0
}

func bfs(id vertexId, vqueue []vertexId, vertices []vertex) {
	vertex := &vertices[id-1]
	for _, vid := range vertex.adjs {
		if !vertices[vid-1].isVisited() {
			(&vertices[vid-1]).visitedAt = vertex.visitedAt+1
			vqueue = append(vqueue, vid)
		}
	}
	if len(vqueue) > 0 {
		nextId := vqueue[0]
		nextVqueue := vqueue[1:]
		bfs(nextId, nextVqueue, vertices)
	}
}

func solveBfs(vertices []vertex) {
	vertex := &vertices[0]
	vertex.visitedAt = 0
	vqueue := make([]vertexId, 0)
	bfs(vertex.id, vqueue, vertices)
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	solveBfs(vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d\n", vertices[i].id, vertices[i].visitedAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func nextInt(sc *bufio.Scanner) (int, error) {
	return strconv.Atoi(nextText(sc))
}

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

using namespace std;

#define MAX 110
int num;
int matrix[MAX][MAX];
int dst[MAX];

void input(){
    for(int i=0;i<MAX;i++){
        dst[i] = -1;
        for(int j=0;j<MAX;j++){
            matrix[i][j] = 0;
        }
    }
    for(int i=1;i<=num;i++){
        int v; cin >> v;
        int tmp; cin >>tmp;
        for(int j=0;j<tmp;j++){
            int vi; cin >> vi;
            matrix[v-1][vi-1] = 1;
        }
    }
}

void bfs(){
    queue<int> Q;
    Q.push(0);
    dst[0] = 0;
    while(Q.size() != 0){
        int cur = Q.front();
        for(int i=0;i<num;i++){
            if(matrix[cur][i]==1){
                if(dst[i]==-1){
                    Q.push(i);
                    dst[i] = dst[cur] + 1;
                }
            }
        }
        Q.pop();
    }
    for(int i=0;i<num;i++){
        cout << i+1 << " " <<  dst[i] << endl;
    }
}

int main(){
    cin >> num;
    input();
    bfs();
}

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

using namespace std;

int main()
{
  bool firstFlag = true;
  int N, u, k, v, frontNum, ansNum;
  int depth = 0;

  cin >> N;
  vector<vector<int> > G(N, vector<int>(N, 0));
  vector<int> ansList(N, -1);
  queue<int> q, r;

  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;
    }
  }
  q.push(0);
  ansList[0] = 0;
  while(!q.empty()){
    frontNum = q.front();
    q.pop();
    for (int i = 0; i < N;i++){
      if(G[frontNum][i] == 0)continue;
      if(ansList[i] != -1)continue;
      ansList[i] = ansList[frontNum] + 1;
      q.push(i);
    }
  }
  for (int i = 0; i < ansList.size();i++){
    cout << i + 1 << " " << ansList[i] << endl;
  }
  return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;
static const int N=100;
static const int INFTY =(1<<21);

int n,M[N][N];
int d[N];//?????¢??§?¨??????¶???(color)???????????????

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) {
		for (int j = 0; j < n; ++j) {
			M[i][j]=0;
		}
	}
	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 <iostream>
#include <stack>
#define NIL -1
#define N 110

using namespace std;

bool A[N + 1][N + 1];
int d[N + 1];
int n;

stack<int> s1;
stack<int> s2;

void bfs(int depth, stack<int> si, stack<int> so) {
  if (si.empty()) return;
  while (!si.empty()) {
    int u = si.top();
    si.pop();
    for (int v = 1; v <= n; v++) {
      if (A[u][v] && d[v] == NIL) {
        so.push(v);
        d[v] = depth;
      }
    }
  }
  bfs(depth + 1, so, si);
}

int main() {

  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++) {
    int u, k, v;
    cin >> u >> k;
    for (int j = 1; j <= k; j++) {
      cin >> v;
      A[u][v] = true;
    }
  }

  for (int i = 1; i <= N; i++) d[i] = NIL;
  s1.push(1);
  d[1] = 0;
  bfs(1, s1, s2);

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

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;
}