Go: package main

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

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Scan()
	num, _ := strconv.Atoi(sc.Text())
	nodes := make(map[int]*node)

	for i := 0; i < num; i++ {
		sc.Scan()
		id, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		nodeNum, _ := strconv.Atoi(sc.Text())
		n := node{id, make([]int, 0), -1}
		for j := 0; j < nodeNum; j++ {
			sc.Scan()
			nid, _ := strconv.Atoi(sc.Text())
			n.nexts = append(n.nexts, nid)
		}
		nodes[id] = &n
	}
	nodes[1].depth = 0

	walk(1, 0, &nodes)
	for i := 1; i < len(nodes)+1; i++ {
		fmt.Printf("%v %v\n", (*nodes[i]).id, (*nodes[i]).depth)
	}
}

var time int
var record [100][100]bool
var q Queue

func walk(nid int, from int, nodes *map[int]*node) {
	q.Enqueue((*nodes)[nid])
	for !q.IsEmpty() {
		n := q.Dequeue().(*node)
		for _, v := range n.nexts {
			n2 := (*nodes)[v]
			if n2.depth != -1 {
				continue
			}
			n2.depth = n.depth + 1
			q.Enqueue((*nodes)[v])
		}
	}
}

type node struct {
	id    int
	nexts []int
	depth int
}

// Queue is Queue
type Queue struct {
	val []interface{}
}

// Enqueue value
func (queue *Queue) Enqueue(val interface{}) {
	queue.val = append(queue.val, val)
}

// Dequeue value
func (queue *Queue) Dequeue() interface{} {
	res := queue.val[0]
	queue.val = queue.val[1:len(queue.val)]
	return res
}

// IsEmpty return true when queue is empty
func (queue *Queue) IsEmpty() bool {
	return len(queue.val) == 0
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define repr(i, n) for (int i = (n); i >= 0; --i)
#define FOR(i, m, n) for (int i = (m); i < (n); ++i)
#define FORR(i, m, n) for (int i = (m); i >= (n); --i)
using namespace std;
typedef long long ll;
const ll mod = 1000000007;
const ll mod2 = 998244353;
const int N = 100;
const int INF = 1<<21;
int n, M[N][N];
int d[N];

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

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

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

typedef long long ll;


int d[200];
bool table[200][200];

void init(){
    for(int i=0;i<200;i++){
        d[i]=-1;
        for(int j=0;j<200;j++){
            table[i][j]=false;
        }
    }
}

void bfs(int itr, int dis, int n){
    d[itr] = dis;
    for(int i=0;i<n;i++){
        if(table[itr][i]&&(d[i]<0||d[i]>dis+1)){
            bfs(i, dis+1,n);
        }
    }
}

void solve(int n){
    bfs(0,0,n);
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);

    init();
    int n;
    cin >> n;
    int u,k,v;
    for(int i=0;i<n;i++){
        cin >> u >> k;
        for(int j=0;j<k;j++){
            cin >> v;
            table[u-1][v-1]=true;
        }
    }

    solve(n);

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

    return 0;
}

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

int main() {
	int a[101][101] = {{0}};
	int u, k, v, km;
	km = 0;
	while ( cin >> u, k ) {
		for ( int i = 1; i <= k; i++ ) {
			cin >> v;
			a[u][v] = 1;
		}
		km++;
	}
	int n0;
	int b[km + 1] = {- 1};
	queue<int> q;
	q.push( 1 );
	b[1] = 0;
	int cou = 0;
	for ( int i = 1; i <= km; i++ ) {
		n0 = q.front();
		q.pop();
		cou++;
		for ( int j = 1; j <= km + 1; j++ ) {
			if ( a[n0][j] == 1 && b[j] == - 1 ) {
				q.push( j );
				b[j] = cou;
			}
			if ( q.empty ) break;
		}
	}
	for ( int i = 1; i <= km; i++ )
		cout << i << " " << b[i] << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
int N,mas[101][101],v[101],cnt=0,st[101];
queue<int> q;

void bfs(int u){
    v[u]++;
    //st[u]=cnt;
    q.push(u);
    while(!q.empty()){
        int n=q.front();
        q.pop();
        for(int i=1;i<N+1;i++){
            if(mas[n][i] && !v[i]){
                v[i]++;
                st[i]=st[n]+1;
                q.push(i);
            }
        }
    }
}

int main(void){
    // Your code here!
    int u,k,vx;
    cin>>N;
    
    for(int i=1;i<N+1;i++){
        cin>>u>>k;
        for(int j=1;j<k+1;j++){
            cin>>vx;
            mas[u][vx]++;
        }
    }
    
    bfs(1);
    for(int i=1;i<N+1;i++){
        if(i>1&& !st[i]) cout<<i<<" "<<"-1"<<endl;       
        else cout<<i<<" "<<st[i]<<endl;  
    } 
}

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];

void dfs(int a){
  queue<int> q;
  q.push(a);
  for(int i=0;i<n;i++) d[i]=INFTY;
  d[a]=0;
  int b;
  while(!q.empty()){
    b=q.front();
    q.pop();
    for(int j=0;j<n;j++){
      if(m[b][j]==0) continue;
      if(d[j]!=INFTY) continue;
      d[j]=d[b]+1;
      q.push(j);
    }
  }
  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;
    }
  }
  dfs(0);
  return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;
#define N 100

int graph[N][N];
int dis[N];
int check[N];
int n;
queue<int> q;

void init(){
    cin>>n;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            graph[i][j] = 0;  //图初始化
        }
        check[i]=0;           //标记数组初始化
        dis[i] = -1;
    }
    int v,count,x;
    for(int i=0;i<n;i++){
        cin>>v;
        cin>>count;
        for(int i=0;i<count;i++){
            cin>>x;
            graph[v-1][x-1]=1;
        }
    }
    q.push(1);
    check[0]=1;
    dis[0]= 0;
}

int BFS(int v){
    for(int i=0;i<n;i++){
        if(graph[v-1][i]>0&&check[i]==0){
            q.push(i+1);
            check[i]=1;
            dis[i] = dis[v-1]+1;
        }
    }
    q.pop();
}

int main(){
    init();
    while(q.size()>0){
        BFS(q.front());
    }
    for(int i=0;i<n;i++){
        cout<<i+1<<" "<<dis[i]<<endl;
    }
    return 0;
}