Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

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

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Queue struct {
	arr []int
}

func (q *Queue) push(v int) {
	q.arr = append(q.arr, v)
}

func (q *Queue) pop() int {
	res := q.arr[0]
	q.arr = q.arr[1:]
	return res
}

func (q *Queue) isEmpty() bool {
	return len(q.arr) == 0
}

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	var q Queue
	seen := make([]int, N)
	for i := 0; i < N; i++ {
		seen[i] = -1
	}
	var search func(cur int)
	search = func(cur int) {
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if seen[next] == -1 {
				q.push(next)
				seen[next] = seen[cur] + 1
			}
		}
	}
	q.push(0)
	seen[0] = 0
	for !q.isEmpty() {
		search(q.pop())
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i+1, seen[i])
	}
	wtr.Flush()
}

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

typedef long long ll;

int main()
{
    ll i,j;
    ll n;
    cin >> n;
    vector<vector<ll>> graph(n);
    for(i = 0;i < n;++i){
        ll u,k,v;
        cin >> u >> k;
        --u;
        for(j = 0;j < k;++j){
            cin >> v;
            --v;
            graph.at(u).push_back(v);
        }
    }
    queue<ll> que;
    vector<ll> visit(n,false);
    que.push(0);
    visit.at(0) = true;
    vector<ll> ans(n,-1);
    ans.at(0) = 0;
    while(!que.empty()){
        ll s = que.front();
        que.pop();
        ll dis = ans.at(s);
        for(i = 0;i < graph.at(s).size();++i){
            ll g = graph.at(s).at(i);
            if(visit.at(g)){
                continue;
            }
            ans.at(g) = dis+1;
            visit.at(g) = true;
            que.push(g);
        }
    }
    for(i = 0;i < n;++i){
        cout << i+1  << " " << ans.at(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;
}

C++: #include<iostream>
#include<vector>
#include<queue>
#include<algorithm>

using namespace std;

int main() {
	int n, u, k, v;
	cin >> n;
	vector<int> ans(n,1000000000);
	vector<vector<int>> adj(n);
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		while (k--)cin >> v, adj[u-1].push_back(v-1);
	}
	queue<pair<int, int>> q;//<idx,path>
	q.push(pair<int, int>(0, 1));
	while (!q.empty()) {
		auto tmp = q.front(); q.pop();
		ans[tmp.first] = min(ans[tmp.first], tmp.second);
		for (int i = 0; i < adj[tmp.first].size(); i++) q.push(pair<int, int>(adj[tmp.first][i], tmp.second+1));
	}
	for (int i = 0; i < n; i++)	cout << i + 1 << " " << (ans[i] == 1000000000 ? -1 : ans[i]-1) << endl;
	
}

C++: #include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>

#include <iostream>
#include <complex>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>

#include <functional>
#include <cassert>

typedef long long ll;
using namespace std;

#define debug(x) cerr << __LINE__ << " : " << #x << " = " << (x) << endl;

#define mod 1000000007 //1e9+7(prime number)
#define INF 1000000000 //1e9
#define LLINF 2000000000000000000LL //2e18
#define SIZE 100010


int main(){
  int n;
  bool connected[200][200] = {};
  
  scanf("%d", &n);

  for(int i=0;i<n;i++){
    int u, k, v;

    scanf("%d%d", &u, &k);
    u--;
    
    for(int j=0;j<k;j++){
      scanf("%d", &v);
      v--;

      connected[u][v] = true;
    }
  }

  queue<int> q1, q2;
  bool visited[200] = {};
  int ans[200];

  for(int i=0;i<n;i++) ans[i] = -1;
  
  q1.push(0);

  for(int i=0;q1.size();i++){

    while(q1.size()){
      int p = q1.front();
      q1.pop();

      if(visited[p]) continue;
      visited[p] = true;

      ans[p] = i;
      
      for(int j=0;j<n;j++){
        if(connected[p][j]){
          q2.push(j);
        }
      }
    }

    q1 = q2;
    q2 = queue<int>();
  }

  for(int i=0;i<n;i++)
    printf("%d\n", ans[i]);
  
  return 0;
}