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 <iostream>
#include <stdio.h>
#include <queue>

using namespace std;
#define N 100
#define INF 2000000

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

void bfs(int s){
	int i,u,v;

	queue<int> q;
	q.push(s);
	for(i=0;i<n;i++){
		d[i] = INF;
	}

	d[s] = 0;

	while(!q.empty()){
		u = q.front();
		q.pop();
		for(v=0;v<n;v++){
			if(M[u][v] == 0) continue;
			if(d[v] != INF) continue;
			d[v] = d[u] + 1;
			q.push(v);
		}
	}
	for(i=0;i<n;i++){
		if(d[i] == INF){
			printf("%d -1\n",i+1);
		}else{
			printf("%d %d\n",i+1,d[i]);
		}
	}
}


int main(void){
	int i,j,u,k,v;

	scanf("%d",&n);

	for(i=0;i<n;i++){
		for(j=0;j<n;j++){
			M[i][j] = 0;
		}
	}

	for(i=0;i<n;i++){
		scanf("%d%d",&u,&k);
		u--;
		for(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;

int D[100100];//始点からの距離を入れる
int g[1001][1001]={{0}};//要素を0で初期化
void bfs(int src,int n){//srcは開始位置この場合だと頂点1だから0
  cerr << "bfs_root = " << src << endl;
  queue<int> Q;
  Q.push(src);
  D[src] = 0;
  while (! Q.empty()  ){
    int cur = Q.front();
    Q.pop();
    // cerr << "visiting_" << cur << " " <<D[cur] <<endl;
    for(int dst= 0; dst < n; dst++){
      if(g[cur][dst]==1 && D[dst]==0){
        D[dst]=D[cur]+1;
        Q.push(dst);
      }
    }
  }
}
void ans(int n){
  for (int i = 0; i < n; ++i)
  {
    cout << i+1 <<" "<<D[i]<<endl;
  }

}

int main(){
  // int g[1001][1001]={{0}};//要素を0で初期化
  int n,a,b,c;
  cin >> n;
  for (int i = 0; i < n; ++i)
  {
    cin >> a >> b ;
    for (int i = 0; i < b; ++i)
    {
      cin >> c;
      g[a-1][c-1]=1;/* code */
    }
  }
  bfs(0,n);
  ans(n);
  // for (int i = 0; i < n; ++i)
  // {
  //    for (int j = 0; j < n; ++j)
  //    {
  //     if (j==n-1)
  //     {
  //       cout << g[i][j] << endl;
  //     }else{
  //       cout << g[i][j] <<" ";
  //     }
  //    }
  // }


}

C++: #define _USE_MATH_DEFINES

#include <array>
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <utility>
#include <tuple>
#include <algorithm>
#include <limits>
#include <fstream>
#include <numeric>
#include <stack>
#include <queue>
#include <list>
#include <cstring>
#include <unordered_set>
#include <cmath>
#include <iomanip>

namespace
{
	template<int N>
	std::array<int, N> GetValue(std::istream& stream)
	{
		std::string buf;
		std::getline(stream, buf);

		std::stringstream sstr(buf);
		std::array<int, N> retval;

		for (int i = 0; i < N; ++i)
		{
			std::getline(sstr, buf, ' ');
			retval[i] = std::stoi(buf);
		}

		return retval;
	}

	std::vector<int> GetValue(std::istream& stream, int num, char delim)
	{
		std::string buf;
		std::getline(stream, buf);
		std::stringstream sstr(buf);

		std::vector<int> retval;
		retval.reserve(num);

		std::string input;;
		for (int i = 0; i < num && std::getline(sstr, input, delim); ++i)
		{
			retval.push_back(std::stoi(input));
		}

		return retval;
	}

	int GetValue(std::istream& stream)
	{
		int in;
		stream >> in;

		return in;
	}

	std::vector<std::string> GetValueString(std::istream& stream, int num, char delim)
	{
		std::string buf;
		std::vector<std::string> retval;
		retval.reserve(num);

		std::getline(stream, buf);
		std::stringstream sstr(buf);

		for (int i = 0; i < num && std::getline(sstr, buf, delim); ++i)
		{
			retval.push_back(std::move(buf));
		}

		return retval;
	}

	template<typename Itr>
	void PrintLine(Itr begin, Itr end)
	{
		bool first = true;

		for (int i = 0; begin != end; ++begin, ++i)
		{
			if (!first)
			{
				std::cout << ' ';
			}

			std::cout << (*begin);

			first = false;
		}
		std::cout << std::endl;
	}

	template<typename T>
	void Print(const std::vector<T>& sequence)
	{
		for (const auto& e : sequence)
		{
			std::cout << e << '\n';
		}

		std::cout << std::flush;
	}

	const int N = 100;
	int Adj[N][N] = {};
	int distance[N];

	void Bfs(int node, int num)
	{
		std::queue<int> q;
		q.push(node);
		for (int i = 0; i < N; ++i)
		{
			distance[i] = std::numeric_limits<int>::max();
		}

		distance[node] = 0;

		int u;
		while (!q.empty())
		{
			u = q.front();
			q.pop();
			for (int v = 0; v < num; ++v)
			{
				if (Adj[u][v] == 0)
				{
					continue;
				}

				if (distance[v] != std::numeric_limits<int>::max())
				{
					continue;
				}

				distance[v] = distance[u] + 1;
				q.push(v);
			}
		}
	}
}

int main(int argc, char* argv[])
{
	auto file = (argc == 1) ? std::ifstream() : std::ifstream(argv[1]);
	std::istream& stream = (argc == 1) ? std::cin : file;
	if (argc == 1)
	{
		std::cin.tie(0);
		std::ios::sync_with_stdio(false);
	}

	int num;
	stream >> num;

	int node, degree;
	int t;

	for (int i = 0; i < num; ++i)
	{
		stream >> node >> degree;
		for (int j = 0; j < degree; ++j)
		{
			stream >> t;
			Adj[node - 1][t - 1] = 1;
		}
	}

	Bfs(0, num);

	for (int i = 0; i < num; ++i)
	{
		std::cout << i + 1 << ' ' << 
			((distance[i] == std::numeric_limits<int>::max()) ? -1 : distance[i]) <<
			std::endl;
	}
}

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

queue<pair<int,int> > qu;
vector<int> v[111];
int root;
int b;
int d[111];
pair<int, int> pa;
int g;

void wide(int num){

  memset(d,-1,sizeof(d));
  d[num] = 0;
  qu.push(make_pair(num,d[1]));

  while(!qu.empty()){

    pa = qu.front();
    qu.pop();
    int id = pa.first;

    for(int i = 0; i < (int)v[id].size(); i++){
      if(d[v[id][i]] == -1){
	d[v[id][i]] = pa.second + 1;
	qu.push(make_pair(v[id][i],d[v[id][i]]));
      }
    }
  }
  for(int i = 1; i <= g; i++){
    cout << i << " " << d[i] << endl;
  }

}

int main(){

 
  cin >> g;
  int n;
  for(int i = 0; i < g; i++){
    cin >> n >> b;
    for(int j = 0; j < b; j++){
      cin >> root;
      v[n].push_back(root);
    }
  }

  wide(1);

}