Go: package main

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

type Pair struct {
	v int
	d int
}

type Queue []Pair

func (q *Queue) push(v Pair) {
	*q = append(*q, v)
}

func (q *Queue) pop() Pair {
	v := (*q)[0]
	*q = (*q)[1:]
	return v
}

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

	nVerts := scanInt(sc)
	graph := make([][]int, nVerts+1)

	for i := 0; i < nVerts; i++ {
		u := scanInt(sc)
		nDegrees := scanInt(sc)

		graph[u] = make([]int, nDegrees)
		for d := 0; d < nDegrees; d++ {
			graph[u][d] = scanInt(sc)
		}
	}

	paths := make([]int, nVerts+1)

	queue := Queue(make([]Pair, 0))
	queue.push(Pair{1, 1})
	paths[1] = 1

	for len(queue) > 0 {
		p := queue.pop()
		d := p.d + 1
		for _, v := range graph[p.v] {
			if paths[v] == 0 {
				paths[v] = d
				queue.push(Pair{v, d})
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 1; i <= nVerts; i++ {
		fmt.Fprintf(w, "%d %d\n", i, paths[i]-1)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

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;
    }
}

C++: #include<iostream>
#include<queue>
using namespace std;
#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define INFTY 999999

int n,M[N][N];
int d[N];
queue<int> q;

void bfs(int s)
{
   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,node;
    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;//row
        if(i==u-1)
        {
            cin >> node;//number of node
            for(int j=0;j<node;j++)
            {
                cin >> v;
                M[i][v-1]=1;
            }
        }
    }

    /*
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)
        {
            cout << M[i][j] << " " ;
        }
        cout << endl;
    }*/

    bfs(0);
    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;
    }
}

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

const int MAX = 100;
int n;
int G[MAX + 1][MAX + 1];
int states[MAX + 1];
int d[MAX + 1];
queue<int> Q;

void bfs(int id) {
  d[id] = 0;
  Q.push(id);

  while (!Q.empty()) {
    id = Q.front(); Q.pop();
    for (int i = 0; i < n; i++) {
      if (G[id][i] == 1 && states[i] == 0) {
        Q.push(i);
        states[i] = 1;
        d[i] = d[id] + 1;
      }
    }
  }
}

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

  cin >> n;

  int u, v, k;

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

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

  bfs(0);

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

  return 0;
}