Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

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

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	n := len(list)
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list[0 : n-1] {
		buf.Write([]byte(fmt.Sprintf("%d ", v)))
	}
	buf.Write([]byte(fmt.Sprintf("%d\n", list[n-1])))
	buf.Flush()
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

//solve
const INFTY = (1 << 21)
const MAX = 100
const WHITE = 0
const GRAY = 1
const BLACK = 2

var time, n int

//隣接行列
var M [MAX][MAX]int

//d[i]: 頂点1から頂点iまでの距離
var color, d [MAX]int

func bfs(s int) {
	var q []int
	q = append(q, s)
	for i := 0; i < n; i++ {
		d[i] = INFTY
	}
	//sは開始点なので、0をいれる
	d[s] = 0

	//キューが空になるまで、以下を繰り返す
	for len(q) > 0 {
		u := q[0]
		q = q[1:]
		for v := 0; v < n; v++ {
			if M[u][v] == 0 {
				continue
			}
			if d[v] != INFTY {
				continue
			}
			d[v] = d[u] + 1
			q = append(q, v)
		}
	}

	for i := 0; i < n; i++ {
		fmt.Printf("%d ", i+1)
		if d[i] == INFTY {
			fmt.Printf("%d\n", -1)
		} else {
			fmt.Printf("%d\n", d[i])
		}
	}
}

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 0; i < n; i++ {
		u, k := nextInt(), nextInt()
		M[u-1][u-1] = 0

		//fmt.Println(u, k)
		if k > 0 {
			for j := 0; j < k; j++ {

				v := nextInt()
				M[u-1][v-1] = 1

			}
		}

	}

	bfs(0)

}

C++: #include <bits/stdc++.h>
#define N 100
#define INFTY (1<<21)

using namespace std;

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++) {
		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>
#include<queue>

using namespace std;
static const int N=100;
static const int INF=(1<<21);

int n,M[N][N];
int d[N];
void breadth(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++){
    cout << i+1 << " " << ((d[i]==INF) ? (-1) : d[i])<<endl;
  }
}
int main(){
  int u,k,v;
  int i,j;
  cin >> n;
  for(i=0;i<n;i++){
    for(j=0;j<n;j++)M[i][j]=0;
  }
  for(i=0;i<n;i++){
    cin >> u >> k;
    u--;
    for(j=0;j<k;j++){
      cin >> v;
      v--;
      M[u][v]=1;
    }
  }
  breadth(0);

  return 0;
}

C++: #include <stdio.h>
#include <queue>

int time, n;
int d[100], color[100];
int M[100][100];

void bfs(int s) {
    std::queue<int> Q;
    
    for (int i=0; i<100; i++) color[i] = 0:
    for (int i=0; i<100; i++) d[i] = -1;
    
    color[s] = 1;
    d[s] = 0;
    Q.push(s);
    while (!Q.empty()) {
        int u = Q.front(); Q.pop();
        for (int i=0; i<n; i++) {
            if(M[u][i] && color[i] == 0) {
                color[i] = 1;
                d[i] = d[u]+1;
                Q.push(i);
            }
        }
        color[u] = 2;
    }
}

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

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

const int nIMPOS = -1;
struct StDist
{
  int m_nDist;
  int m_nDone;

  StDist(int nDist) : m_nDist(nDist), m_nDone(0)
  { }
};

void fnInput(vector<vector<int>>& rvvnAdjcy, vector<StDist>& rvoDist)
{
  int nxSiz;
  cin >> nxSiz;

  rvvnAdjcy.resize(nxSiz + 1, vector<int>(nxSiz + 1, 0));
  for (int i = 0; i < nxSiz; ++i)
  {
    int nx, nySiz;
    cin >> nx >> nySiz;
    for (int j = 0; j < nySiz; ++j)
    {
      int ny;
      cin >> ny;
      rvvnAdjcy[nx][ny] = 1;
    }
  }
  StDist oDist(nIMPOS);
  rvoDist.resize(nxSiz + 1, oDist);
}

void fnBreadthFirstSearch(const vector<vector<int>>& cnrvvnAdjcy, 
                          queue<int>& rqnBFSrch, vector<StDist>& rvoDist)
{
  while (rqnBFSrch.size())
  {
    int nx = rqnBFSrch.front(); rqnBFSrch.pop();
    if (rvoDist[nx].m_nDist == nIMPOS)  continue;

    for (int ny = 1; ny < cnrvvnAdjcy[nx].size(); ++ny)
    {
      if (cnrvvnAdjcy[nx][ny] == 1  &&
          rvoDist[nx].m_nDone == 0)
      {
        int nDist = rvoDist[nx].m_nDist + 1;
        if (rvoDist[ny].m_nDist == nIMPOS)
          rvoDist[ny].m_nDist = nDist;
        else
          rvoDist[ny].m_nDist = min(rvoDist[ny].m_nDist, nDist);

        rqnBFSrch.push(ny);
      }
    }
    rvoDist[nx].m_nDone = 1;
  }
}

void fnResult(const vector<StDist>& cnrvoDist)
{
  for (int i = 1; i < cnrvoDist.size(); ++i)
    cout << i <<  " " << cnrvoDist[i].m_nDist << endl;
}

int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  vector<vector<int>> vvnAdjcy;
  queue<int>  qnBFSrch;
  vector<StDist> voDist;

  fnInput(vvnAdjcy, voDist);

  voDist[1].m_nDist = 0;
  qnBFSrch.push(1);
  fnBreadthFirstSearch(vvnAdjcy, qnBFSrch, voDist);
  fnResult(voDist);

  return 0;
}

C++: #include<iostream>
#include<iomanip>
#include<algorithm>
#include<string>
#include<vector>
#include<deque>
#include<queue>

using std::cout;
using std::cin;
using std::setw;
using std::setfill;
using std::string;
using std::pair;
using std::make_pair;
using std::vector;
using std::queue;
using std::deque;
using std::priority_queue;
using std::next_permutation;
//using std::iota;
using std::sort;
using std::greater;
using std::max;
using std::min;

#define INF 999999999;
#define MOD 1000000007

#define EVEL 1

#ifndef EVEL
#define dbug(X) std::cout << #X << ":" <<X<<" " ;
#define dbugf(s) std::cout << s << " ";
#define dbugln std::cout<<"\n";
#else
#define dbug(X) {}
#define dbugf(s) {}
#define dbugln {}
#endif

int n;
vector<vector<int>> l;
queue<pair<int, int>> lq;
int Min[100];
bool flag[100];

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

    cin >> n;
    l.resize(n);
    for(int i = 0; i < n; i++){
        Min[i] = -1;
        int u, k, v;
        cin >> u >> k;
        for(int j = 0; j < k; j++){
            cin >> v;
            l[u-1].push_back(v-1);
        }
    }

    lq.push(make_pair(0, 0));
    while(!lq.empty()){

        pair<int, int> f = lq.front();lq.pop();
        dbug(f.first)dbug(f.second)dbugln;
        if(Min[f.first] == -1)Min[f.first] = f.second;
        else Min[f.first] = min(f.second, Min[f.first]);
        dbug(Min[f.first])dbugln;
        if(!flag[f.first]){
            for(int i = 0; i < l[f.first].size(); i++){
                lq.push(make_pair( l[f.first][i], f.second+1 ));
                dbug(l[f.first][i])dbug(f.second+1)dbugln;
            }
        }
        flag[f.first] = true;
        dbugln
    }

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

    return 0;
}