Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	visitedAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		visitedAt: -1,
		adjs: adjs,
	}
}

func (v *vertex) isVisited() bool {
	return v.visitedAt >= 0
}

func bfs(id vertexId, vqueue []vertexId, vertices []vertex) {
	vertex := &vertices[id-1]
	for _, vid := range vertex.adjs {
		if !vertices[vid-1].isVisited() {
			(&vertices[vid-1]).visitedAt = vertex.visitedAt+1
			vqueue = append(vqueue, vid)
		}
	}
	if len(vqueue) > 0 {
		nextId := vqueue[0]
		nextVqueue := vqueue[1:]
		bfs(nextId, nextVqueue, vertices)
	}
}

func solveBfs(vertices []vertex) {
	vertex := &vertices[0]
	vertex.visitedAt = 0
	vqueue := make([]vertexId, 0)
	bfs(vertex.id, vqueue, vertices)
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	solveBfs(vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d\n", vertices[i].id, vertices[i].visitedAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func nextInt(sc *bufio.Scanner) (int, error) {
	return strconv.Atoi(nextText(sc))
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <list>
#include <map>
#include <set>
#include <string>
#include <cstring>
#include <sstream>
#include <cmath>
#include <functional>
#include <fstream>
#include <cstdlib>
typedef long long ll;
const int MOD = 1e9+7;


#define REP(i, N) for (int i = 0; i < (N); i++)
#define REPP(i, a, b) for (int i = (a); i < (b); i++)
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define VSORT(c) sort((c).begin(),(c).end())
#define SZ(x) ((int)(x).size())
//vvintを作る　マクロで　 #define vvint(N,M) vector<vector<int>>

using namespace std;


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

    int n;
    cin >> n;
    int d[n+1];
    REPP(i,1,n+1) d[i] = -1;
    int hoge,num;
    vector<vector<int> > bfs(n+1);
    for(int i = 1; i < n+1;i++){
        cin >> hoge >> num;
        for(int l = 0; l < num;l++){
            int tmp;
            cin >> tmp;
            bfs[i].push_back(tmp);
        }
    }

    // 初期セットアップ(index=1)
    queue<pair<int, int> > queue;
    for(int i = 0; i < bfs[1].size();i++){
        queue.push(make_pair(1,bfs[1][i]));
    }
    d[1] = 0;

    while(!queue.empty()){
        if(d[queue.front().second] == -1){
            d[queue.front().second] = d[queue.front().first]+1;
            for(int i = 0; i < bfs[queue.front().second].size();i++){
                queue.push(make_pair(queue.front().second,bfs[queue.front().second][i]));
            }
        }
        queue.pop();
    }

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

    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;
    for(int j=0;j<k;j++){
      cin>>v;
      v--;
      m[u][v]=1;
    }
  }

  bfs(0);

  return 0;
}

C++: // -*- mode:c++; coding:utf-8; c-basic-offset:2; -*-
// ALDS1_11_C: Breadth First Search

#include <algorithm>
#include <cstdio>
#include <queue>

using uint = unsigned int;

class Graph {
  const uint n_;
  uint* const g_;
  uint* const depth_;
  
public:
  Graph(uint n) : n_(n),
                  g_(new uint[(n_*n_)]),
                  depth_(new uint[n])
  {
    std::fill(g_, g_+(n_*n_), 0u);
  }

  ~Graph()
  {
    delete[] g_;
    delete[] depth_;
  }
  
  uint* operator [](uint i) const { return g_+(n_*i); }

  uint* depth() const { return depth_; }

  void bfs()
  {
    init_depth();
    std::queue<uint> q;
    auto i = 0u;
    q.push(i);
    depth_[i] = 0u;
    auto last_visit = i;
    while (!q.empty()) {
      i = q.front();
      for (auto j = last_visit+1; j < n_; ++j) {
        if ((*this)[i][j] && !depth_[j]) {
          q.push(j);
          depth_[j] = depth_[i]+1;
        }
      }
      q.pop();
      last_visit = i;
    }
  }

private:
  void init_depth()
  {
    std::fill(depth_, depth_+(n_), 0u);
  }
};

int main()
{
  uint n;
  std::scanf("%u", &n);

  Graph g(n);

  uint u, k, v;
  for (auto i = 0u; i < n; ++i) {
    std::scanf("%u %u", &u, &k);
    for (auto j = 0u; j < k; ++j) {
      std::scanf("%u", &v);
      g[u-1][v-1] = 1;
    }
  }

  g.bfs();
  auto depth = g.depth();
  for (auto i = 0u; i < n; ++i) {
    std::printf("%u %u\n", i+1, depth[i]);
  }
}

// eof

C++: #include<iostream>
#include<vector>
#include<queue>
#include<algorithm>
using namespace std;
const int MAXN = 10000;
int n;
int vs[MAXN];
int d[MAXN];
void bfs(int s,vector<vector<int> > &g){
  queue<int> q;
  q.push(s);
  fill(d,d+MAXN,-1);
  d[s] = 0;
  while(!q.empty()){
    int current = q.front();q.pop();
    for(int next:g[current]){
      if(d[next] < 0){
        q.push(next);
        d[next] = d[current] + 1;
      }
    }
  }
}
int main(){
  cin >> n;
  vector<vector<int> > g(n+1);
  for(int i = 1;i <= n;i++){
    int u,k;
    cin >> u >> k;
    for(int j = 0; j < k;j++){
      int v;
      cin >> v;
      g[u].push_back(v);
    }
  }
  bfs(1,g);
  for(int i = 1;i <= n;i++){
    cout << i << ' ' << d[i] << endl;
  }
}

C++: #include <bits/stdc++.h>
using namespace std;
#define _GLIBCXX_DEBUG
typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<pair<int, int>, int> PP;
// const ll INF = 1LL << 60;
const ll MOD = 1000000007;
const int INF = 1000000000;
const int MAX = 300000;

int GCD(int a, int b) { return b ? GCD(b, a % b) : a; }
//------------------------------------------------------------------------------------------------------------------------------

vector<vector<int>> G;
vector<int> d;
bool visit[1000];
void bfs(int s) {
    queue<int> que;
    visit[s] = 1;
    d[s] = 0;
    que.push(s);
    while (!que.empty()) {
        int v = que.front();
        que.pop();
        for (auto nv : G[v]) {
            if (visit[nv]) {
                continue;
            }
            visit[nv] = 1;
            d[nv] = d[v] + 1;
            que.push(nv);
        }
    }
}
int main(void) { 
    int N;
    cin >> N;
    G.resize(N);
    d.assign(N, -1);
    for (int i = 0; i < N; i++) {
        int u, k;
        cin >> u >> k;
        u--;
        for(int i = 0; i < k; i++) {
            int v;
            cin >> v;
            v--;
            G[u].push_back(v);
        }
    }
    bfs(0);
    for(int i = 0; i < N; i++) {
        cout << i + 1 << ' ' << d[i] << endl;
    }
}