Go: package main

/*
グラフの表現 隣接行列による表現
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		g[i] = make([]int, n+1)
		ints := eGetInts(scanner)
		num := ints[0]
		for j := 0; j < ints[1]; j++ {
			g[num][ints[j+2]] = 1
		}
	}
	dist := make([]int, n+1)
	for i := 0; i < len(dist); i++ {
		dist[i] = -1
	}
	q := []int{}

	// 訪問する
	q = append(q, 1)
	dist[1] = 0

	// キューが空でない限り
	for len(q) > 0 {
		// 先頭を取り出す
		top := 0
		top, q = q[0], q[1:]
		// 隣接マスを入れる.
		for i := 1; i < n+1; i++ {
			// 辺がある
			if g[top][i] == 1 {
				if dist[i] == -1 {
					// 訪問済みでなければ
					q = append(q, i)
					dist[i] = dist[top] + 1
				}
			}
		}
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, dist[i])
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

C++: #include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, a, b) for (int i = a; i < b; ++i)
#define FORR(i, a, b) for (int i = b - 1; i >= a; --i)
#define SORT(v) sort(v.begin(), v.end())
#define SORTR(v) sort(v.rbegin(), v.rend())
#define REV(v) reverse(v.begin(), v.end())
#define ITER(itr, v) for (auto itr = v.begin(); itr != v.end(); ++itr)
#define LB(v, x) (lower_bound(v.begin(), v.end(), x) - v.begin())
#define UB(v, x) (upper_bound(v.begin(), v.end(), x) - v.begin())
#define SZ(v) (int)v.size()
using namespace std;
using ll = long long;
using P = pair<int, int>;

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

	int n;
	cin >> n;
	vector<vector<int>> edge(n + 1);
	FOR(i, 1, n + 1) {
		int u, k;
		cin >> u >> k;
		REP(j, k) {
			int v;
			cin >> v;
			edge[u].emplace_back(v);
		}
	}
	vector<int> d(n + 1, -1);
	d[1] = 0;
	queue<int> qu;
	qu.emplace(1);
	while (!qu.empty()) {
		int i = qu.front();
		qu.pop();
		for (auto &j : edge[i]) {
			if (d[j] < 0) {
				d[j] = d[i] + 1;
				qu.emplace(j);
			}
		}
	}
	FOR(i, 1, n + 1) {
		cout << i << " " << d[i] << endl;
	}

	return 0;
}

C++: #define _USE_MATH_DEFINES
#include<stdio.h>
#include<string>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include<queue>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include<iomanip>

//#include<bits/stdc++.h>



using namespace std;




int main() {
	
	int n;
	cin>>n;
	vector<vector<int>>t(n,vector<int>(0));
	for(int i=0;i<n;i++){
		int a,b;
		cin>>a>>b;
		for(int j=0;j<b;j++){
			int x;
			cin>>x;x--;t[i].push_back(x);
		}
	}
	queue<int>r;
	r.push(0);
	int g[105]={1000000};
	for(int i=0;i<n;i++){
		g[i]=10000000;
	}
	g[0]=0;
	set<int>p;
	p.insert(0);
	bool f[105]={};
	while(r.size()||p.size()<n){
		if(!r.size()){
			for(int i=0;i<n;i++){
				if(g[i]==10000000){
					g[i]=-1;
					p.insert(i);
					//r.push(i);
				}
			}
		}
		else{
		int v=r.front();
		for(int i=0;i<t[v].size();i++){
			if(!f[t[v][i]]){
				f[t[v][i]]=1;
			r.push(t[v][i]);
			p.insert(t[v][i]);
			g[t[v][i]]=min(g[t[v][i]],g[v]+1);
			}
			
		}
		r.pop();
		
		}
	}
	for(int i=0;i<n;i++)
		cout<<i+1<<" "<<g[i]<<endl;

	
	return 0;
}

C++: #include <bits/stdc++.h>
#define PI 3.14159265359
#define NIL (-1)
using namespace std;
const int64_t MOD = 1e9 + 7;

int n;
vector<vector<int>> M(100, vector<int>(100));
vector<int> d(100), C(100);
static const int INFTY = INT_MAX;

void bfs(int s) {
	for (int i = 0; i < n; i++) {
		C.at(i) = 0;
		d.at(i) = INFTY;
	}

	C.at(s) = 1;
	d.at(s) = 0;
	queue<int>q;
	q.push(s);

	while (!q.empty()) {
		int u = q.front();
		q.pop();

		for (int i = 0; i < n; i++) {
			if (M.at(u).at(i) && (C.at(i) == 0)) {
				C.at(i) = 1;
				d.at(i) = d.at(u) + 1;
				q.push(i);
			}
		}

		C.at(u) = 2;
	}

	for (int i= 0; i < n; i++) {
		cout << i + 1 << ' ' << (d.at(i) == INFTY ? -1 : d.at(i)) << endl;
	}
}

int main() {
	int u, k, v;
	cin >> n;

	for (int i = 0; i < n; i++) {
		cin >> v >> k;

		for (int j = 0; j < k; j++) {
			int x;
			cin >> x;
			M.at(v - 1).at(x - 1) = true;
		}
	}

	bfs(0);

	return 0;
}

C++: #include<stdio.h>
#include<stack>
#include<iostream>
#include<string>
using namespace std;

int n = 0;
int u = 0;
int k[101];
int v[101][101];
int Short[101] = { 0 };
//into n = 0;
int p = 0;
int fptr = 0;
int lptr = 0;
int x1[10000];
int y1[10000];
void Enqueue(int y, int x)
{
	x1[lptr] = x;
	y1[lptr] = y;
	lptr = (lptr + 1) % n;
}
void bfs(int l) {
	int i;
	while (fptr!=lptr) {
		l=x1[fptr];
		p=y1[fptr];
		fptr = (fptr + 1) % n;
		if(Short[l]!=-1){
			continue;
		}
		for(i=0;i<k[l];i++){
			if(v[l][i]){
				Enqueue(p+1,v[l][i]);
			}
		}
		//Enqueue(v[l][in]);
		Short[l]=++p;
	}
}
int main()
{
	int i;
	int j;
	cin >> n;
	for (i = 0; i < n; i++) {
		cin >> u;
		cin >> k[u];
		for (j = 0; j < k[u]; j++) {
			cin >> v[u][j];
		}
	}
	Enqueue(-1,1);
	for(i=0;i<n+1;i++){
		Short[i]=-1;
	}
	bfs(0);
	cout << "\n";
	
	for (i = 1; i < n + 1; i++) {
		cout << i << " " << Short[i] << endl;
	}
}