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 <iostream>
#include <stdio.h>
#include <queue>
#define N 101
#define INFTY (1<<21)


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

void bfs(int u) {
    std::queue<int> Q;
    Q.push(u);
    for (int i = 0; i < n; i++) d[i] = INFTY;
    d[u] = 0;
    while ( ! Q.empty() ) {
        int j = Q.front();
        Q.pop();
        for (int v = 0; v < n; v++) {
            if (M[j][v] == 0) continue;
            if (d[v] != INFTY) continue;
            d[v] = d[j] + 1;
            Q.push(v);
        }
    }
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i+1, d[i]);
    }
}

int main() {
    int u, k, v;
    scanf("%d", &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++) {
        scanf("%d %d", &u, &k);
        u--;
        if (k == 0) continue;
        for (int j = 0; j < k; j++) {
            scanf("%d", &v);
            v--;
            M[u][v] = 1;
        }
    }
    
    bfs(0);
    
    return 0;
}

C++: #include <iostream>
#include <queue>
using namespace std;
 
#define N 100
#define INFTY 1000000
 
int M[N][N],d[N];
int n,u,k,v;
 
//bfs
void bfs(int s){
 
  queue <int> Q;
  //十分大きな数字に初期化
  for(int i = 0; i < N; i++ ) d[i] = INFTY;
  
  //最初の訪問先
  d[s] = 0;
  Q.push(s);

  //Qが空でないとき
  while ( !Q.empty() ){

    //queueから出す
    u = Q.front(); Q.pop();

    for( int v = 0; v < n; v++ ){

      //つながってないとき
      if( M[u][v] == 0 ) continue;

      //既に訪問ずみのとき
      if( d[v] != INFTY ) continue;

      //時間を入力
      d[v] = d[u] + 1;

      //queueに追加
      Q.push(v);
    }
  }
 
  //出力
  for( int i = 0; i < n; i++ ){
    cout << i+1 << " ";
    if ( d[i] == INFTY ) cout << -1;
    else cout << d[i];
    cout << endl;
  }
 
}
 
 
int main(){

  //初期化
  for( int i = 0; i < n; i++ ){
    for( int j = 0; j < n; j++ ) M[u][v] = 0;
  }
  
  //入力
  cin >> n;
  for( int i = 0; i < n; i++ ){
    cin >> u;
    u--;
    cin >> k;
    for( int j = 0; j < k; j++ ){
      cin >> v;
      v--;
      //つながっているとき
      M[u][v] = 1;
    }
  }
  
  //bfs
  bfs(0);
   
  return 0;
}

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

using namespace std;

vector<int> d(101, -1);
vector<vector<int> > c(101, vector<int>(101, 0));

int n, u, k, v;
typedef pair<int, int> P; 
int bfs(void) {
    queue<P> que;
    que.push(P(0, 0));
    while(que.size()>0) {
        P p = que.front(); que.pop();
        if(d[p.first]==-1) d[p.first] = p.second;
        for(int i=0; i<n; ++i) {
            if(c[p.first][i]==1 && d[i]==-1) que.push(P(i, d[p.first]+1));
        }
    }
}

int main() {
    cin >> n;
    for(int i=0; i<n; ++i) {
        cin >> u >> k;
        for(int j=0; j<k; ++j) {
            cin >> v;
            c[i][v-1] = 1;
        }
    }
    bfs();
    for(int i=0; i<n; ++i) {
        cout << i+1 << " " << d[i] << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define r(i,n) for(auto i=0;i<n;i++)
#define s(c) static_cast<int>((c).size())

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

	set<int> A[n+1];
	int v1, v2, deg;
	r(i, n){
		cin >> v1 >> deg;

		r(j, deg){
			cin >> v2;
			A[v1].insert(v2);
		}
	}

	queue<int> s;
	s.push(1);
	int dist[n+1]{0, 1};

	while(!s.empty()){
		int v1 = s.front(); s.pop();
		for(int v2 : A[v1]){
			if(!dist[v2]){
				s.push(v2);
				dist[v2] = dist[v1]+1;
			}
		}
	}

	for(int i = 1; i <= n; i++)
		printf("%d %d\n", i, dist[i]-1);

	return 0;
}

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

class Vtx {
public:
	int id;
	int dist = -1;
	vector<int> vtxs;
};

void dfs(int n, Vtx vtxs[]){
	queue<pair<int,int> > q;
	q.push(make_pair(vtxs[0].id, 0));
	while(!q.empty()){
		pair<int,int> p=q.front();
		q.pop();
		int id=p.first-1;
		int d=p.second;
		Vtx v = vtxs[id];
		if(v.dist==-1){
			vtxs[id].dist=d;
		}
		for(int i=0;i<v.vtxs.size();i++){
			int nId=v.vtxs[i];
			if(vtxs[nId-1].dist==-1){
				q.push(make_pair(nId,d+1));
			}
		}
	}
}

int main(){
	int n;
	cin >> n;
	Vtx vtxs[n];
	for(int i=0;i<n;i++){
		int id, k;
		cin >> id >> k;
		vtxs[i].id = id;
		for(int j=0;j<k;j++){
			int v;
			cin >> v;
			vtxs[i].vtxs.push_back(v);
		}
	}
	
	dfs(n, vtxs);
	
	for(int i=0;i<n;i++){
		Vtx v = vtxs[i];
		cout << v.id << " ";
		cout << v.dist << 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++){
    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;
}