Go: package main

import (
	"fmt"
	"os"
	"bufio"
	"strconv"
	"container/list"
)

const MaxNode int = 100

var d []int
var A [][]int
var N int
var l *list.List

func bfs(u int) {
	d[u] = 0
	l.PushBack(u)
	for ;l.Len() != 0; {
		u = l.Front().Value.(int)
		l.Remove(l.Front())
		for v:=0; v<N; v++ {
			if A[u][v] == 0 {
				continue
			}
			if d[v] != -1 {
				continue
			}
			d[v] = d[u] + 1
			l.PushBack(v)
		}
	}
}


func nextInt(scanner *bufio.Scanner) int {
	scanner.Scan()
	num, _ := strconv.Atoi(scanner.Text())
	return num
}

func print() {
	for i:=0; i<N; i++ {
		fmt.Printf("%d %d\n", i+1, d[i])
	}
}

func initVariable() {
	d = make([]int, MaxNode)
	A = make([][]int, MaxNode)
	l = list.New()
	for i:=0; i<MaxNode; i++ {
		A[i] = make([]int, MaxNode)
		d[i] = -1
	}
}


func main() {
	initVariable()
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	N = nextInt(scanner)
	for i:=0; i<N; i++ {
		idx := nextInt(scanner)
		cnt := nextInt(scanner)
		for j:=0; j<cnt; j++ {
			node := nextInt(scanner)
			A[idx-1][node-1] = 1 
		}
	}
	bfs(0)
	print()
}

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

int main(int argc,char* argv[]){
  int dis[101],flag[101];
  vector<queue<int> > vec(101);
  int n,id,cnt,x,val=0;

  memset(dis,255,sizeof(dis));
  memset(flag,0,sizeof(flag));

  cin>>n;
  for(int i=0;i<n;i++){
    cin>>id>>cnt;
    queue<int> tmp;
    for(int l=0;l<cnt;l++){
      cin>>x;
      tmp.push(x);
    }
    vec[id]=tmp;
  }

  queue<int> que;
  que.push(1);
  while(!que.empty()){
    queue<int> tmp=que;
    while(!que.empty())
      que.pop();
    int p;

    while(!tmp.empty()){
      p=tmp.front();tmp.pop();
      if(dis[p]==-1)
	dis[p]=val;

      while(!vec[p].empty()){
	que.push(vec[p].front());
	vec[p].pop();
      }
    }
    val++;
  }

  for(int i=1;i<=n;i++)
    printf("%d %d\n",i,dis[i]);

  return 0;
}

C++: #include<iostream>
#include<vector>
#include<queue>
using namespace std;
#define MAX 101

vector<int> G[MAX];

int bfs(int id){
	queue<int> Q;
	int temp[MAX] = {}, ans = -1;
	
	Q.push(1);
	
	while(!Q.empty()){
		int n = Q.front(); Q.pop();
		if(n == id){
			ans = temp[n];
			break;
		}
		for(int y : G[n]){
			if(temp[y]==0&&y!=1){
				temp[y] += temp[n] + 1;
				Q.push(y);
			}
		}
	}
	return ans;
}

int main(){
	int n, u, k, v, A[MAX][MAX] = {};
	
	cin>>n;
	
	for(int i = 0; i < n; i++){
		cin>>u>>k;
		for(int j = 0; j < k; j++){
			cin>>v;
			G[u].push_back(v);
		}
	}
	
	for(int i = 1; i <= n; i++){
		cout<<i<<" "<<bfs(i)<<endl;
	}
	
	
	return 0;
}

C++: #include "bits/stdc++.h"
#define REP(i, n) for(int i = 0; i < n; i++)
#define REPR(i, n) for(int i = n; i >= 0; i--)
#define FOR(i, m, n) for(int i = m; i < n; i++)
#define FORR(i, a, b) for(int i=(b)-1; i>=(a); --i)
#define ALL(v) v.begin(), v.end()
#define FS first
#define SC second
#define SZ(a) int((a).size())
#define SORT(c) sort((c).begin(),(c).end())
#define MEMSET(v, h) memset((v), h, sizeof(v))
#define sqr(x) ((x) * (x))
#define bit(n) (1LL<<(n))
#define pcnt(x) __builtin_popcountll(x)
#define PB push_back
#define MP make_pair
#define endl "\n"
using namespace std;
typedef long long LL;
typedef long double LD;
typedef vector<int> VI;
typedef vector<LL> VLL;
typedef vector<bool> VB;
typedef vector<vector<int> > VVI;
typedef vector<vector<bool> > VVB;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef vector<PII> VPII;
const LL MOD=1000000007ll;
const LL INF=2000000000ll;

long power(long a,long b){return b?power(a*a%MOD,b/2)*(b%2?a:1)%MOD:1;}

long perm(int N, int K){
	long x=1;
	for(int i=1;i<=K;i++)
	{
		x=x*(N-i+1)%MOD;
	}
	return x%MOD;
}

long factorial(int N){
	return perm(N,N);
}

long comb(int N,int K){
	long x=1,y=1;
	for(int i=1;i<=K;i++)
	{
		x=x*(N-i+1)%MOD;
		y=y*i%MOD;
	}
	return x*power(y,MOD-2)%MOD;
}

long hcomb(int N, int K){
    return comb(N+K-1, N-1);
}

void dfs(const vector<vector<int> > &G, int v, vector<int> &seen) {
    seen[v] = true; // v を訪問済にする

    // v から行ける各頂点 next_v について
    for (auto next_v : G[v]) { 
        if (seen[next_v]) continue; // next_v が探索済だったらスルー
        dfs(G, next_v, seen); // 再帰的に探索
    }
}

void wfs(const vector<vector<int> > &G, int v, vector<int> &dist){
    REP(i,SZ(dist)) dist[i] = -1; // 全頂点を「未訪問」に初期化
    queue<int> que;

    // 初期条件 (頂点 0 を初期ノードとする)
    dist[v] = 0;
    que.push(v); // 0 を橙色頂点にする

    // BFS 開始 (キューが空になるまで探索を行う)
    while (!que.empty()) {
        v = que.front(); // キューから先頭頂点を取り出す
        que.pop();

        // v から辿れる頂点をすべて調べる
        for (int next_v : G[v]) {
            if (dist[next_v] != -1) continue; // すでに発見済みの頂点は探索しない

            // 新たな白色頂点 nv について距離情報を更新してキューに追加する
            dist[next_v] = dist[v] + 1;
            que.push(next_v);
        }
    }
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(10);

	int n, u, k;
	cin >> n;
	VVI G(n);
	REP(i,n){
		cin >> u >> k;
		if(k){
			G[i].resize(k);
			REP(j,k){
				cin >> G[i][j];
				G[i][j]--;
			}
		}
	}

	VI d(n);
	wfs(G,0,d);
	REP(i,n) cout << i+1 << " " << d[i] << endl;

}