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>
#include <cstdlib>
#include <cassert>
#include <string>
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>

using namespace std;

// ---------------------
// repetition
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

// debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

// ---------------------
#define INF 922337203685477580
typedef long long ll;

int matrix[110][110];
int dist[110];
int visited[110];
int n;
queue<int> Q;

int main() {
  REP(x, 110) {
    REP(y, 110) {
      matrix[x][y] = 0;
    }
    dist[x] = (1 << 15);
    visited[x] = 0;
  }

  // int n;
  cin >> n;

  REP(_, n) {
    int v, num;
    cin >> v >> num;

    REP(i, num) {
      int cv;
      cin >> cv;
      matrix[v][cv] = 1;
    }
  }

  dist[1] = 0;
  Q.push(1);

  while (!Q.empty()) {
    int f = Q.front(); Q.pop();
    visited[f] = 1;

    // int updated = 0;
    FOR(v, 1, n + 1) {
      if (matrix[f][v]) {
        if (dist[v] > dist[f] + 1) {
          dist[v] = dist[f] + 1;
          // updated = 1;
          // cout << "update for " << v  << endl;
        }
        if (!visited[v]) {
          Q.push(v);
        }
      }
    }
    // if (updated == 0 && Q.empty()) {
    //   cout << "break!" << endl;
    //   break;
    // }
  }


  FOR(v, 1, n + 1) {
    if (dist[v] == (1 << 15)) {
      cout << v << " -1" << endl;
    } else {
      cout << v << " " << dist[v] << endl;
    }
  }


  return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <iostream>
#include <string>
#include <map>
#include <queue>
#include <stdio.h>
#include <math.h>


using namespace std;

typedef long long ll;

typedef vector<vector<int>> vvi;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<ll> vll;

typedef pair<int, int> P;

typedef queue<int> qi;
typedef queue<string> qs;


#define rep(i, n) for(int i=0; i<(n); ++i)
#define repp(i, a, b) for(int i = (a); i <= (b); i++)
#define Rep(i, n) for(int i=n; i >= 0; i--)

#define all(v) v.begin(), v.end()
//sort( all(v) )　などと使える

int main() {
	int n; cin >> n;
	vector<vector<int>> G(n);
	rep(i, n) {
		int u, k; cin >> u >> k;
		u--;
		//G[u].resize(k);

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

	vector<int> dist(n, -1);

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

	while (!que.empty()) {
		int v = que.front();
		que.pop();

		for (auto nv : G[v]) {
			if (dist[nv] != -1) continue;
			else {
				dist[nv] = dist[v] + 1;
				que.push(nv);
			}
		}
	}

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

	//return 0;
}

C++: #include <cstdio>

void search(int (*A)[101], int *dis, int *found, int n){
    int hoge;
    int time=0;
    for(int k=1;k<n;k++){
        hoge = 1;
        for(int i=1;i<=n;i++){
            if(dis[i]==time){
                for(int j=1;j<=n;j++){
                    if(A[i][j]&&found[j]==0){
                        found[j]=1;
                        dis[j]=time+1;
                        hoge=0;
                    }
                }
            }
        }
        time++;
        if(hoge)return;
    }
}

int main(){
    int i, j, n, u, k, v;
    scanf("%d",&n);
    int found[n+1];
    int dis[n+1];
    dis[1]=0;
    found[1]=1;
    for(i=2;i<=n;i++){
        dis[i]=-1;
        found[i]=0;
    }
    int A[101][101];
    for(i=1;i<=n;i++){
        for(j=1;j<=n;j++){
            A[i][j]=0;
        }
    }
    for(i=1;i<=n;i++){
        scanf("%d %d",&u,&k);
        for(j=0;j<k;j++){
            scanf("%d",&v);
            A[u][v]=1;
        }
    }
    search(A,dis,found,n);
    for(i=1;i<=n;i++)printf("%d %d\n",i,dis[i]);
    return 0;
}

C++: #include <cstdio>
#include <cstring>
#include <queue>
#define N 110
#define INF 0x3f3f3f3f
using namespace std;
//stack<int> s;
int n;
int m[N][N];
int used[N];
int d[N];
void bfs(int root){
    queue<int>q;
    while(!q.empty()) q.pop();
    q.push(root);
    d[root] = 0;
    while(!q.empty()){
        int u = q.front();
        used[u] = 1;
        q.pop();
        for(int i = 1; i <= n; i++){
            if(used[i] == 0 && m[u][i]){
                q.push(i);
                d[i] = d[u] + 1;
                used[i] = 1;
            }
        }
    }
}
int main(){
    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++) used[i] = 0;
    for(int i = 0; i < N; i++) d[i] = INF;
    scanf("%d", &n);
    for(int p = 0; p < n; p++){
        int node, k;
        scanf("%d %d", &node, &k);
        for(int i = 0; i < k; i++){
            int b;
            scanf("%d", &b);
            m[node][b] = 1;
        }
    }
    bfs(1);
    //for(int i = 1; i <= n; i++) if(used[i] == 0) bfs(i);
    for(int i = 1; i <= n; i++){
        printf("%d %d\n", i, d[i] == INF ? -1 : d[i]);
    }
    return 0;
}