Go: package main

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

const MAX = 1000
const NIL = -1

type Node struct {
	id    int
	depth int
}

type Queue struct {
	head      int
	tail      int
	container [MAX]Node
}

func (q *Queue) inQueue(x Node) {
	q.container[q.tail] = x
	q.tail = (q.tail + 1) % MAX
}

func (q *Queue) deQueue() Node {
	x := q.container[q.head]
	q.head = (q.head + 1) % MAX
	return x
}

func (q *Queue) isEmpty() bool {
	return q.head == q.tail
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()
	route := make([][]int, n)
	for i := range route {
		u, k := scanInt(), scanInt()
		u--
		route[u] = make([]int, k)
		for j := range route[u] {
			num := scanInt()
			num--
			route[i][j] = num
		}
	}

	d := make([]int, n)
	for i := range d {
		d[i] = NIL
	}

	start := Node{0, 0}
	que := Queue{}
	que.inQueue(start)
	for !que.isEmpty() {
		node := que.deQueue()
		if d[node.id] != NIL {
			continue
		}
		d[node.id] = node.depth

		for _, nextId := range route[node.id] {
			next := Node{id: nextId, depth: node.depth + 1}
			que.inQueue(next)
		}
	}

	for i, depth := range d {
		fmt.Println(i+1, depth)
	}
}

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

/////////////////////////////////////////////////////////////////////

template<typename T>
vector<T> BFS(vector<vector<int>> &G, int s) {
    vector<T> ret(G.size(),-1);
    ret[s] = 0;
    queue<int> que;
    que.emplace(s);
    while (!que.empty()) {
        int v = que.front(); que.pop();
        for (auto nv : G[v]) {
            if (ret[nv] != -1) continue;
            ret[nv] = ret[v] + 1;
            que.emplace(nv);
        }
    }

    return ret;
}

////////////////////////////////////////////////////////////////////

int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    int N; cin >> N;
    vector<vector<int>> G(N);
    for (int i = 0; i < N; ++i) {
        int u,k; cin >> u >> k;
        for (int j = 0; j < k; ++j) {
            int v; cin >> v;
            --v;
            G[i].emplace_back(v);
        }
    }

    auto dist = BFS<int>(G,0);

    for (int i = 0; i < N; ++i) cout << i+1 << " " << dist[i] << endl;
}

/*
  verified on 2020/02/18
  http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_C&lang=ja
*/

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;

}

C++: #include <iostream>
using namespace	std;
int n,g[100][100],f[100],c[100];
void bfs(int now,int far){
  f[now]=far;
  c[now]=1;
  far++;
  for(int i=0;i<n;i++) if(g[now][i]&&c[i]!=1) bfs(i,far);

}
int main(){

  int a,b,tmp;
  cin>>n;
  for(int i=0;i<n;i++){
    f[i]=-1;
    cin>>a>>b;
    for(int j=0;j<b;j++){
      cin>>tmp;
      g[a-1][tmp-1]=1;
    }
  }

  bfs(0,0);

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

  return 0;

}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <complex>
#include <stack>
#include <queue>
#include <list>
#include <utility>
#include <set>
using namespace std;

int main(){
    int n;
    cin >> n;
    int g[200][200];
    int i, j;
    int u, k, v;
    int dist[200];
    bool visited[200];
    
    for(i = 0; i < n; i++){
        dist[i] = -1;
        for(j = 0; j < n; j++){
            g[i][j] = 0;
        }
    }
    
    for(i = 0; i < n; i++){
        cin >> u >> k;
        u--;
        for(j = 0; j < k; j++){
            cin >> v;
            v--;
            g[u][v] = 1;
        }
    }
    
    queue<int> q1, q2;
    q1.push(0);
    
    for(i = 0; q1.size(); i++){
        while(!q1.empty()){
            int p = q1.front();
            q1.pop();
            
            if(visited[p]) continue;
            visited[p] = true;
            
            dist[p] = i;
            
            for(j = 0; j < n; j++){
                if(g[p][j]){
                    q2.push(j);
                }
            }
        }
        q1 = q2;
        q2 = queue<int>();
    }
    
    for(i = 0; i < n; i++){
        cout << i+1 << " " << dist[i] << endl;
    }
}

C++: #define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define int long long
#define rep(i,n) for(int i=0;i<n;i++)
#define Rep(i,a,b) for(int i=a;i<b;i++)
#define REP(i,a,b) for(int i=a;i<=b;i++)
#define rev(i,n) for(int i=n-1;i>=0;i--)
#define vi vector<int>
#define pb push_back
#define pi pair<int,int>
#define vp vector<pair<int,int>>
#define mp make_pair
#define all(v) (v).begin(),(v).end()
#define fi first
#define se second
#define MEMSET(a) memset(a,0,sizeof(a))
#define inf (1ll<<60)

using namespace std;

const int mod=1e9+7;

void run();

void init() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout<<fixed<<setprecision(12);
}

signed main(){
    init();
    run();
    return 0;
}

#define N 100
int n;
int d[N];

void bfs(vector<vi> a,int s){
    rep(i,n)d[i]=inf;
    queue<int> q;
    q.push(s);
    d[0]=0;
    while(!q.empty()){
        int v=q.front();
        q.pop();
        for(int u:a[v]){
            if(d[u]!=inf)continue;
            d[u]=d[v]+1;
            q.push(u);
        }
    }
}

void run(){
    cin>>n;
    vector<vi> a(n);
    rep(i,n){
        int u,k;
        cin>>u>>k;
        u--;
        rep(j,k){
            int v;
            cin>>v;
            v--;
            a[u].pb(v);
        }
    }
    bfs(a,0);
    rep(i,n){
        cout<<i+1<<" "<<(d[i]!=inf?d[i]:-1)<<endl;
    }
}

C++: #include <iostream>
#include <vector>
#include <queue>
#include <cstring>
#define INFTY 1000000000
using namespace std;
bool list[100][100];
int ti[100];
int n;

void bfs(int now){
	queue<int> next;
	next.push(now);
	while(next.size()!=0){
		now=next.front();	next.pop();
		for(int i=0;i<n;i++){
			if(list[now][i]&&ti[i]==INFTY){
				ti[i]=ti[now]+1;
				next.push(i);
			}
		}
	}
}

int main(){
	for(int i=0;i<100;i++){
		for(int j=0;j<100;j++)	list[i][j]=false;
		ti[i]=INFTY;
	}
	cin>>n;
	int id,num,ne;
	for(int i=0;i<n;i++){
		cin>>id>>num;
		id--;
		for(int j=0;j<num;j++){
			cin>>ne;
			list[id][ne-1]=true;
		}
	}
	ti[0]=0;	bfs(0);
	for(int i=0;i<n;i++){
		cout<<i+1<<" "<<((ti[i]==INFTY)?(-1):ti[i])<<endl;
	}
	return 0;
}

C++: #include<cstdio>
#include<vector>
#include<algorithm>
#include<utility>
#include<numeric>
#include<iostream>
#include<array>
#include<string>
#include<sstream>
#include<stack>
#include<queue>
#include<list>
#define _USE_MATH_DEFINES

#include<math.h>
#include<map>

#define SENTINEL 1000000001

#define min(a,b) (a)>(b)?(b):(a)
#define max(a,b) (a)>(b)?(a):(b)

using namespace std;

int G[101][101];
int d[101];

void explore(int id, int n,int cnt)
{
	if (cnt == n)
	{
		return;
	}
	if (d[id] == -1)
	{
		d[id] = cnt;
	}
	else
	{
		d[id] = min(d[id], cnt);
	}

	for (int i = 1; i <= n; i++)
	{
		if (G[id][i] == 1)
		{
			explore(i, n, cnt + 1);
		}
	}
}

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

	for (int i = 0; i < n; i++)
	{
		int id, k;
		cin >> id >> k;

		for (int i = 0; i < k; i++)
		{
			int v;
			cin >> v;
			G[id][v] = 1;
		}
	}

	for (int i = 1; i <= 100; i++)
	{
		d[i] = -1;
	}

	explore(1, n, 0);

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

	return 0;
}