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 <utility>
#include <string>
#include <vector>
#include <algorithm>
#include <iostream>
using namespace std;

int n;
int a[100][100] = {0};
int k[100] = {0};
int d[100];

int kansu( int i, int t ){
	if ( d[i] != -1 && d[i] <= t ) return 0;
	d[i] = t;
	t++;
	for ( int j = 0; j < k[i]; j++ ) {
		kansu( a[i][j], t );
	}
	return 0;
}

int main(){
	cin >> n;
	int s;
	for ( int i = 0; i < n; i++ ) {
		cin >> s;
		cin >> k[i];
		for ( int j = 0; j < k[i]; j++ ) {
			cin >> s;
			a[i][j] = s-1;
		}
	}
	for ( int i = 0; i < n; i++ ) {
		d[i] = -1;
	}
	kansu(0,0);
	for ( int i = 0; i < n; i++ ) {
		cout << i+1 << " " << d[i] << endl;
	}
	return 0;
}

C++: /*
AizuOJ ALDS1_11_C

???;BFS;????´¢;?????????;?¨????
*/
#include <queue>
#include <cstring>
#include <cstdio>
using namespace std;

const int MAXN=110, MAXM=110*110, INF=0x3f3f3f3f;
int n;
int adj[MAXN]; // 1 .. n
int to[MAXM], enext[MAXM]; // 1 .. m
int d[MAXN];

int s, v;
void bfs(int start) {
    queue<int> q;
    q.push(start);
    while (!q.empty()) {
        s=q.front();
        q.pop();
        for (int e=adj[s]; e!=0; e=enext[e]) {
            v=to[e];
            if (d[v]>d[s]+1) {
                d[v]=d[s]+1;
                q.push(v); // ?????????????????? !visited
            }
        }
    }
}

void add_edge(int no, int u, int v) {
    to[no]=v;
    enext[no]=adj[u];
    adj[u]=no;
}

int m=0, k, tmp;
//int v;
int main() {
    memset(d, INF, sizeof(d));
    d[1]=0;
    scanf("%d", &n);
    for (int u=1; u<=n; u++) {
        scanf("%d%d", &tmp, &k);
        while (k--) {
            scanf("%d", &v);
            add_edge(++m, u, v);
        }
    }
    bfs(1);
    for (int u=1; u<=n; u++) {
        printf("%d %d\n", u, d[u]==INF ? -1 : d[u]);
    }
    return 0;
}

C++: #include<stdio.h>
int n=0;
int u=0;
int k[101]={0};
int v[101][101]={0};
int d[101];//d[]=short[].
int cur=0;
int fptr=0;
int lptr=0;
int queue[1024]={};
int q2[1024]={};
int max=sizeof(queue)/sizeof(queue[0]);    //データの数/1データの使用メモリ
void enqueue(int p,int m){
	queue[lptr]=p;
	q2[lptr]=m;
	lptr=(lptr+1)%max;//エンキュー
}
void bfs(void){
	int id=0,m=0;
	while(lptr!=fptr){
	id=queue[fptr];
	m=q2[fptr];
	fptr=(fptr+1)%max;//デキュー
	if(d[id]!=-1){
		continue;
	}
	d[id]=m;
	for(int i=0;i<k[id];i++){
		enqueue(v[id][i],m+1);
	}
	}
	return;
	}
	int main(void)
{
	for(int r=0;r<101;r++){
	d[r]=-1;
	}
	scanf("%d",&n);
	for(int i=0;i<n;i++){
		scanf("%d",&u);
		scanf("%d",&k[u]);
		for(int j=0;j<k[u];j++){
			scanf("%d",&v[u][j]);
		}
	}
		enqueue(1,0);
		
		bfs();
	for(int i=1;i<n+1;i++){
		printf("%d %d\n",i,d[i]);
	}
	return(0);
}

C++: #include<iostream>
using namespace std;
#define NIL -1
int n,ch[200],V[200][200],d[200],a;
void count(int x,int reach){
    d[x]=reach;
    for(int i=1;i<=ch[x];i++){
        int p=V[x][i];
        if(d[p]==NIL||d[p]>reach+1) count(p,reach+1);
    }
}
int main(){
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a>>ch[i];
        d[i]=NIL;
        for(int j=1;j<=ch[i];j++){
            cin>>V[i][j];
        }
    }
    count(1,0);
    for(int i=1;i<=n;i++){
        cout<<i<<" "<<d[i]<<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];

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);
}

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 || 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;
}