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;
using UL = unsigned int;
using ULL = unsigned long long;
using LL = long long;
#define rep(i,n) for(UL i=0; i<(n); i++)

vector<UL> E[100];
UL D[100];

int main() {
 UL N; scanf("%u",&N);
 rep(i,N){
  UL v; scanf("%u",&v); v--;
  UL c; scanf("%u",&c);
  rep(i,c){
   UL e; scanf("%u",&e); e--;
   E[v].push_back(e);
  }
 }
 rep(i,N) D[i]=~0u;
 queue<UL> Q; Q.push(0); D[0]=0;
 while(Q.size()){
  UL p=Q.front(); Q.pop();
  for(UL e:E[p]){
   if(D[e]!=~0u) continue;
   D[e]=D[p]+1;
   Q.push(e);
  }
 }
 rep(i,N){
  printf("%u ",i+1);
  if(D[i]!=~0) printf("%d\n",D[i]);
  else printf("-1\n");
 }
 return 0;
}

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

#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 ALL(obj) (obj).begin(), (obj).end()
#define INF 1e9
typedef long long ll;

using Graph = vector<vector<int>>;

Graph G;

int n;


int main() {
    cin >> n;
    G.assign(n, vector<int>());
    REP(i,n){
        int u;
        cin >> u;
        u--;
        int k;
        cin >> k;
        REP(j,k){
            int v;
            cin >> v;
            v--;
            G[u].push_back(v);
        }
    }
    vector<int> dist(n, -1);
    queue<int> que;

    dist[0] = 0;
    que.push(0);

    while(!que.empty()){
        int v = que.front();
        que.pop();

        for(int next: G[v]){
            if(dist[next]!=-1) continue;

            dist[next] = dist[v] + 1;
            que.push(next);
        }
    }
    REP(i,n){
        cout << i+1 << " " << dist[i] << endl;
    }
    return 0;
}

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

int main(){
  vector<int> G[100];
  queue<int> q;
  vector<int> d(100,-1);
  int n,u,k,v,depth;
  bool flg;
  
  cin >> n;
  for (int i=0;i<n;i++){
    cin >> u>> k;
    for (int j=0;j<k;j++){
      cin >> v;
      G[u-1].push_back(v-1);
    }
  }
  depth=0;
  q.push(0);
  d[0]=depth;
  while (!q.empty()){
    u=q.front();
    for (int i=0;i<G[u].size();i++){
      v=G[u][i];
      if (d[v]==-1){
	q.push(v);
	d[v]=d[u]+1;
	flg=true;
	break;
      }
    }
    if (!flg){
      q.pop();
    }else{
      flg=false;
    }
  }
    
  for (int i=0;i<n;i++)
    cout << i+1 <<" "<< d[i]<<" "<<endl;
  
  return 0;
}

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

typedef struct{
  int A[1000];
  int ans;
  bool c;
}node;
node T[1000];
int Q[10000000];
int head=0;
int tail=1;
int n;

void function(int num){
  while(true){
    if(head==tail)break;
    for(int i=2;i<=n;i++){
      if(T[num].A[i]==1){
	if(T[i].ans==0){
	  T[i].ans=T[num].ans+1;
	  T[num].A[i]=0;
	}
	Q[tail++]=i;
      }
    }
    //    cout<<"Q "<<Q[head]<<endl;
    num=Q[head++];
    //  cout<<head<<" "<<tail<<endl;
  }

}

int main(){
  int num;
  int son;
  int z;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>num;
    cin>>son;
    for(int j=0;j<son;j++){
      cin>>z;
      T[num].A[z]=1;
      }
  }
  Q[0]=1;
  function(1);
  T[1].ans=0;
  for(int i=2;i<=n;i++){
    if(T[i].ans==0){
      T[i].ans=-1;
    }
  }

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


  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define _GLIBCXX_DEBUG
const int INF_INT = 2147483647;
const long long INF_LONG = 9223372036854775807;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

 
int main() {
  int n;
  cin >> n;
  vector<vector<int>> g(n, vector<int>(0));
  rep (i, n) {
    int x, k;
    cin >> x >> k;
    g[i].resize(k);
    rep (j, k) {
      cin >> x;
      g[i][j] = x - 1;
    }
  }

  queue<int> que;
  vector<int> d(n, -1);
  d[0] = 0;

  for (int x : g[0]) {
    que.push(x);
    d[x] = 1;
  }
  while (!que.empty()) {
    int v = que.front(); que.pop();
    for (int vn : g[v]) {
      if (d[vn] != -1) continue;
      d[vn] = d[v] + 1;
      que.push(vn);
    }
  }

  

  rep (i, n) {
    printf("%d %d\n", i + 1, d[i]);
  }
}

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

using namespace std;

#define GRAPH_SIZE 101
#define START_INDEX 1

enum color_t {
  WHITE,
  GRAY,
  BLACK,
};

struct data_t {
  uint32_t index;
  vector<uint32_t> connection;
  uint32_t distance;
};

static vector<uint32_t> graph[GRAPH_SIZE];
static color_t state[GRAPH_SIZE];

void breadth_first_search(void (*callback)(uint32_t, uint32_t))
{
  for (uint32_t i = START_INDEX; i < GRAPH_SIZE; i++) {
    state[i] = WHITE;
  }

  queue<data_t> queue;

  data_t data;
  data.index = START_INDEX;
  data.connection = graph[START_INDEX];
  data.distance = 0;

  queue.push(data);
  state[START_INDEX] = GRAY;

  while (!queue.empty()) {
    data_t top = queue.front();
    queue.pop();

    state[top.index] = BLACK;
    callback(top.index, top.distance);

    for (uint32_t i = 0; i < top.connection.size(); i++) {
      if (state[top.connection[i]] == WHITE) {
        data_t data;
        data.index = top.connection[i];
        data.connection = graph[top.connection[i]];
        data.distance = top.distance + 1;
        queue.push(data);
        state[data.index] = GRAY;
      }
    }
  }
}

#include <iostream>

uint32_t distances[GRAPH_SIZE];

static void callback(uint32_t index, uint32_t distance)
{
  distances[index] = distance;
}

int32_t main()
{
  uint32_t num;
  cin >> num;

  for (uint32_t i = START_INDEX; i < START_INDEX + num; i++) {
    distances[i] = -1;
  }

  for (uint32_t i = 0; i < num; i++) {
    uint32_t index, len;
    cin >> index >> len;
    for (uint32_t j = 0; j < len; j++) {
      uint32_t val;
      cin >> val;
      graph[index].push_back(val);
    }
  }

  breadth_first_search(callback);

  for (uint32_t i = START_INDEX; i < START_INDEX + num; i++) {
    cout << i << " " << distances[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++){
    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;
}