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<iostream>
#include<cstdio>
#define INF 1000000
#define NIL -2
#define GRAY -3
#define WHITE -4
#define BRACK -5

using namespace std;

int n;
int M[101][101];
int d[101];//重み
//int p[101];//親
int color[101];

void Dijkstra(int u) {
	//cout << u << endl;
	color[u] = BRACK;

	//重みの更新
	for (int i = 1; i <= n; i++) {
		if (color[i] != BRACK && M[u][i] != 0) {
			color[i] = GRAY;
			if ((d[u] + M[u][i]) < d[i]) {
				d[i] = d[u] + M[u][i];
			}
		}
		//cout << d[i] << " ";
	}

	//cout << endl;

	int min = -1;
	d[min] = 100000;


	for (int v = 1; v <= n; v++) {
		if (color[v] != BRACK) {
			if (d[v] < d[min]) {
				min = v;
			}
			else {
				color[v] = WHITE;
			}
		}
	}

	if (min != -1) {
		Dijkstra(min);
	}
}

int main() {
	cin >> n;
	int v, k, g, weight; //v = 節点番号　g = 次数

	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			M[i][j] = 0;
		}
	}

	for (int i = 1; i <= n; i++) {
		cin >> v >> g;
		for (int j = 1; j <= g; j++) {
			cin >> k;
			M[i][k] = 1;
		}
	}

	for (int i = 1; i <= n; i++) {
		color[i] = WHITE;
	}

	for (int i = 1; i <= n; i++) {
		d[i] = INF;
		//cout << d[i] << " ";
	}

	d[1] = 0;


	//関数
	Dijkstra(1);


	for (int i = 1; i <= n; i++) {
		if (d[i] == INF) {
			d[i] = -1;
		}
		cout << i << " " << d[i] << endl;
	}

	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 bfs(int s)
{
	queue<int> q;
	q.push(s);
	for(int i=0;i<n;i++) d[i] = INF;
	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] != INF)continue;
			d[v] = d[u]+1;
			q.push(v);
		}
	}
	for(int i=0;i<n;i++){
		cout << i+1 << " " <<((d[i] == INF)?(-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<queue>
using namespace std;
const int MAX = 100;
int n, G[MAX + 1][MAX + 1];
bool book[MAX + 1] = { false };
int path[MAX + 1];
void breathFSearch(int orign)
{
	queue<int> Q;
	Q.push(orign);
	book[orign] = true;
	while (!Q.empty())
	{
		int u = Q.front();
		for (int v = 1; v <= n; v++)
		{
			if (G[u][v] && !book[v])
			{
				Q.push(v);
				book[v] = true;
				if(path[u]!=-1)
					path[v] = path[u]+1;
			}
		}
		Q.pop();
	}
}
int main()
{
	cin >> n;
	for (int i = 1; i <= n; i++)
	{
		int u, d;
		cin >> u >> d;
		for (int j = 1; j <= d; j++)
		{
			int v;
			cin >> v;
			G[u][v] = 1;
		}
	}
	for (int i = 1; i <= n; i++)
		path[i] = -1;
	path[1] = 0;
	for(int i=1;i<=n;i++)
		if(!book[i])
			breathFSearch(i);
	for (int i = 1; i <= n; i++)
		cout << i << " " << path[i] << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define FOR(i, s, e) for (int i = (int)(s); i <= (int)(e); i++)
#define printYesNo(is_ok) puts(is_ok ? "Yes" : "No");
#define SORT(v) sort(v.begin(), v.end());
#define RSORT(v) sort(v.rbegin(), v.rend());
#define REVERSE(v) reverse(v.begin(), v.end());

vector<vector<int> > G;
// bfs 幅優先探索
int bfs(int s)
{
    vector<int> cost(G.size(), -1);

    cost[s] = 0;
    queue<int> pos_queue;
    pos_queue.push(s);

    while (pos_queue.size())
    {
        int pos = pos_queue.front();
        pos_queue.pop();
        rep(i, G[pos].size())
        {
            int next = G[pos][i];

            if (cost[next] == -1)
            {
                cost[next] = cost[pos] + 1;
                pos_queue.push(next);
            }
        }
    }
    rep(i, G.size())
    {
      cout << i + 1 << " " << cost[i] << endl;
    }
}

int main()
{
  int N;
  cin >> N;
  G.resize(N);
  rep(i, N)
  {
    int u, k;
    cin >> u >> k;
    u--;
    rep(j, k)
    {
      int v;
      cin >> v;
      G[u].push_back(v - 1);
    }
  }
  bfs(0);
  return 0;
}

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

int main(){
  int n, u, k, tmp, lp;
  vector<int> d;
  vector< vector<int> > v;
  vector< queue<int> > q;
  
  cin >> n;
  v.resize(n+1);
  d.resize(n+1, 1000000007);
  q.resize(1);
  d[1]=0;
  q[0].push(1);
  
  for (int r = 0; r < n; r++) {
	cin>> u >> k;
    for(int i=0;i<k;i++){
      cin>> tmp;
      v[u].push_back(tmp);
    }
  }
  
  for(int r=0;r<n;r++){
    //cout<< "r=" << r <<endl;
    q.resize(q.size()+1);
    lp=q[r].size();
    for(int i=0;i<lp;i++){
      tmp=q[r].front();
      //cout<< "tmp=" << tmp <<endl;
      q[r].pop();
      for(int j=0;j<v[tmp].size();j++){
        //cout<< "push " << v[tmp][j] << "  val " << min(v[tmp][j], d[tmp]+1) <<endl;
        if(d[v[tmp][j]]>d[tmp]+1){
          q[r+1].push(v[tmp][j]);
      		d[v[tmp][j]]=min(d[v[tmp][j]], d[tmp]+1);
        }
      }
    }
  }
  
  for(int i=1;i<=n;i++){
    cout<< i << " ";
    if(d[i]==1000000007) cout<< "-1" <<endl;
    else cout<< d[i] <<endl;
  }
  
  return 0;
}