Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	nodes := make([]Node, n)

	for i := 0; i < n; i++ {
		nodes[i].list = make([]int, 0)
		nodes[i].d = -1
	}

	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		u--
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			v--
			nodes[u].list = append(nodes[u].list, v)
		}
	}

	queue := make([]int, n)
	queue[0] = 0
	nodes[0].d = 0
	d := 0
	i, j := 0, 1
	for i < j {
		d++
		prev := j
		for i < prev {
			for k, l := 0, len(nodes[queue[i]].list); k < l && i < n; k++ {
				if nodes[nodes[queue[i]].list[k]].d != -1 {
					continue
				}
				nodes[nodes[queue[i]].list[k]].d = d
				queue[j] = nodes[queue[i]].list[k]
				j++
			}
			i++
		}
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i+1, nodes[i].d))
	}

	writer.Flush()
}

// Node ...
type Node struct {
	list []int
	d    int
}

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

static const int MAX_NUM = 101;
static const int NO_VISIT  = 0;
static const int END_VISIT = 2;

void BFS(int *matrix, int num)
{
    int i;
    int state[MAX_NUM]    = {0};
    int distance[MAX_NUM];
    queue<int> Q;
    int target;
    int dist = 0;
    int *tmp;
    bool first;

    for (i = 1; i <= num; i++) {
        distance[i] = -1;
    }

    Q.push(1);
    state[1] = END_VISIT;
    distance[1] = 0;

    while (Q.empty() == false) {
        target = Q.front();
        Q.pop();
        tmp = matrix + target * MAX_NUM;
        first = true;
        for (i = 1; i <= num; i++) {
            if ((*(tmp + i) == 1) && (state[i] == NO_VISIT)) {
                distance[i] = distance[target] + 1;
                Q.push(i);
                state[i] = END_VISIT;
            }
        }
    }

    for (i = 1; i <= num; i++) {
        printf("%d %d\n", i, distance[i]);
    }

    return;
}

int main(void)
{
    int i, j;
    int num;
    int elem;
    int nume;
    int tmp;
    int matrix[MAX_NUM][MAX_NUM];

    scanf("%d", &num);
    for (i = 0; i < num; i++) {
        scanf("%d %d", &elem, &nume);
        for (j = 0; j < nume; j++) {
            scanf("%d", &tmp);
            matrix[elem][tmp] = 1;
        }
    }

    BFS(&matrix[0][0], num);

    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 <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i=0; i<(n); ++i)
using ll = long long;
using P = pair<int, int>;

const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;
const int MAX = 103;
const int INF = -1;
int G[MAX][MAX];
int n;
int color[MAX], dist[MAX];

void bfs(int s) {
  memset(color, WHITE, sizeof(color));
  memset(dist, INF, sizeof(dist));

  queue<int> Q;

  color[s] = GRAY;
  dist[s] = 0;
  Q.push(s);

  while (!Q.empty()) {
    int u = Q.front(); Q.pop();
    rep(v,n) {
      if (G[u][v] && color[v] == WHITE) {
	color[v] = GRAY;
	dist[v] = dist[u] + 1;
	Q.push(v);
      }
    }
    color[u] = BLACK;
  }
}

int main() {
  cin >> n;
  rep(i,n) memset(G[i], 0, sizeof(G[i])); // init
  int u, k;
  rep(i,n) {
    cin >> u >> k;
    rep(j,k) {
      int t;
      cin >> t;
      G[i][t-1] = 1;
    }
  }

  bfs(0);

  rep(i,n) {
    cout << i+1 << ' ' << (dist[i]==INF ? -1 : dist[i]) << endl;
  }
  return 0;
}

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

int d[110];

int main() {
  int n;
  std::cin >> n;
  int G[110][110];
  for(int i=0; i<n; ++i) {
    for(int j=0; j<n; ++j) G[i][j] = 0;
  }

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

  for(int i=0; i<n; ++i) {
    int u, k;
    std::cin >> u >> k;
    u--;
    for(int j=0; j<k; ++j) {
      int v;
      std::cin >> v;
      v--;
      G[u][v] = 1;
    }
  }

  std::queue<int> que;
  que.push(0);
  int dist = 0;
  d[0] = 0;

  while(!que.empty()) {
    // キューから一番最初を取り出す
    int u = que.front();
    que.pop();

    for(int v=0; v<n; ++v) {
      if(G[u][v] == 1 && d[v] == -1) {
        que.push(v);
        d[v] = d[u]+1;
      }
    }
  }

  for(int i=0; i<n; ++i) {
    std::cout << i+1 << " " << d[i] << std::endl;
  }
}