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 <stdio.h>
#define N 100
#define INF 100000000

int G[N+1][N+1], vis[N+1], n, size[N+1];

void dfs(int p, int t){
  int i;
  vis[p] = t;
  for(i=1;i<=size[p];i++) if(t + 1 < vis[G[p][i]]) dfs(G[p][i], t + 1);
}

main(){
  int i, j, u;
  scanf("%d", &n);
  for(i=1;i<=n;i++){
    vis[i] = INF;
    scanf("%d", &u);
    scanf("%d", &size[u]);
    for(j=1;j<=size[u];j++) scanf("%d", &G[u][j]);
  }
  dfs(1, 0);
  for(i=1;i<=n;i++) printf("%d %d\n", i, (vis[i] == INF) ? -1 : vis[i]);
  return 0;
}

C++: #include <iostream>
#include <stdio.h>
#include <vector>
#include <utility>
#include <string>
#include <algorithm>
#include <cmath>
#include <queue>
#include <cstring>
 
typedef long long ll;

#define rep(i,n) for(ll i = 0; i < n; i++)
 
using namespace std;
 
const ll INF = ll(1e18)+1;
const double PI=3.14159265358979323846;

vector<vector<int> > G(105);
vector<int> D(105,-1);

int main(){
  int n;
  cin >> n;
  rep(i,n){
    int u,k;
    cin >> u >> k;
    rep(j,k){
      int v;
      cin >> v;
      G[u].push_back(v);
    }
  }

  queue<int> q;
  q.push(1);
  D[1] = 0;  
  while( !q.empty() ){
    int v = q.front();
    q.pop();
    
    rep(i,G[v].size()){      
      if(D[G[v][i]] != -1) continue;
      D[G[v][i]] = D[v] + 1;
      q.push(G[v][i]);
    }
  }

  rep(i,n){
    cout << i+1 << " " << D[i+1] << endl;
  }
}

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]; //距離で訪問状態(color)を管理する

void bfs(int s){
    queue<int> q; //標準ライブラリのqueueを使用
    q.push(s);
    for(int i=0; i<n; i++) d[i] = INFTY;
    d[s] = 0; //最初の距離をゼロに設定
    int u;
    while(!q.empty()){ //キューがある限りループ
        u = q.front(); q.pop(); //キューを取り出し、削除
        for(int v=0; v<n; v++){
            if(M[u][v] == 0) continue; //初項は飛ばす
            if(d[v] != INFTY) continue; //すでに距離が記録されたものは飛ばす
            d[v] = d[u] + 1; //距離をプラス１して代入
            q.push(v); //キューに追加
        }
    }
    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++){ //隣接リストから隣接行列へ変換
        cin >> u >> k;
        u--;
        for(int j=0; j<k; j++){
            cin >> v;
            v--;
            M[i][v] = 1;
        }
    }

    bfs(0);

    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
  int n;
  cin>>n;
  vector<vector<int> > G(n,vector<int>());
  for(int i=0;i<n;i++){
    int u,k;
    cin>>u>>k;
    u--;
    for(int j=0;j<k;j++){
      int c;
      cin>>c;
      c--;
      G[u].push_back(c);
    }
  }
  int d[n];
  memset(d,-1,sizeof(d));
  queue<int> q;
  d[0]=0;
  q.push(0);
  while(!q.empty()){
    int v=q.front();q.pop();
    for(int u:G[v]){
      if(d[u]<0){
	d[u]=d[v]+1;	
	q.push(u);
      }
    }
  }
  for(int i=0;i<n;i++) cout<<i+1<<" "<<d[i]<<endl;;
  return 0;
}

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

const long N = 100;
const long INFTY = (1<<21);

long n, M[N + 1][N + 1];
long d[N + 1];

void bfs(long s){
	queue<long> q;
	q.push(s);
	for (long i = 1; i <= n; i++) d[i] = INFTY;
	d[s] = 0;
	long u;
	while (!q.empty()){
		u = q.front();
		q.pop();
		for (long v = 1; v <= n; v++){
			if (M[u][v] == 0) continue;
			if (d[v] != INFTY) continue;
			d[v] = d[u] + 1;
			q.push(v);
		}
	}
	for (long i = 1; i <= n; i++){
		cout << i << " " << ((d[i] == INFTY) ? (-1) : d[i]) << endl;
	}
}

int main(){
	long u, k, v;
	cin >> n;
	for (long i = 1; i <= n; i++){
		for (long j = 1; j <= n; j++){
			M[i][j] = 0;
		}
	}
	for (long i = 0; i < n; i++){
		cin >> u >> k;
		for (long j = 0; j < n; j++){
			cin >> v;
			M[u][v] = 1;
		}
	}

	bfs(0);

	return 0;
}

C++: #include<iostream>
#include<queue>
static const int N = 100;
static const int INFTY = (1 << 21);
using namespace std;

int n, M[N][N],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 < n; j++) {
			cin >> v;
			v--;
			M[u][v] = 1;
		}
	}

	bfs(0);

    return 0;
}