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++: // 幅優先探索
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<stack>
#include<algorithm>
#include<iostream>
#include<cmath>
#include<vector>

#include<queue>

using namespace std;

#define MAX_N 100
// 値の定義
const int INV = -1;
const int EXIST = 1;
const int NO_EXIST = 0;

const int YES = 0;
const int NO = -1;

// グラフ情報を保持する配列
int ary_graph[MAX_N + 1][MAX_N + 1];

// 頂点１からの距離を保持する配列
int vertex_distance[MAX_N + 1];
// 頂点１からの訪問状態を保持する配列
int ary_visit[MAX_N + 1];

int n = 0;
int nt[MAX_N + 1];

void widthFirstSearch(int start_vertex);

int main(void)
{
    int u, num, v_num, start_point;

    for(int i = 0; i < MAX_N + 1; i++)
    {
    	vertex_distance[i] = 0;
        ary_visit[i] = NO;

        for(int j = 0; j < MAX_N + 1; j++)
        {
            // 配列の初期化
            ary_graph[i][j] = NO_EXIST;
        }
    }

    cin >> n;

    for(int i = 0; i < n; i++)
    {
        cin >> u >> num;

        // 0オリジンにする
        u--;

        for(int j = 0; j < num; j++)
        {
            // 隣接点を記憶する
            cin >> v_num;

            // 0オリジンにする
            v_num--;
            ary_graph[u][v_num] = EXIST;
        }
    }

    for(int i = 0; i < n; i++)
    {
        if( ary_visit[i] == NO )
        {
            start_point = i;

            // 幅優先探索を実施
            widthFirstSearch(i);
        }
    }

    // 結果の表示
    for(int i = 0; i < n; i++)
    {
        if( i != start_point && vertex_distance[i] == 0 )
        {
            // 開始点から到達不可能な点だった
            vertex_distance[i] = INV;
        }

        printf("%d %d\n", i + 1, vertex_distance[i]);
    }

    return 0;
}

// u に隣接する v を番号順に取得
int next(int u)
{
    int ret = INV;

    for(int v = nt[u]; v < n; v++)
    {
        nt[u] = v + 1;

        if( ary_graph[u][v] == EXIST )
        {
            // 隣接点が存在する
            ret = v;
            break;
        }
    }

    return ret;
}

// 幅優先探索を実施する関数
// start_vertex : 起点となる頂点のNo.
// vertex_num : グラフの頂点数
void widthFirstSearch(int start_vertex)
{

    queue<int> Q;

    Q.push(start_vertex);
    vertex_distance[start_vertex] = 0;
    ary_visit[start_vertex] = YES;

    while( !Q.empty() )
    {
        int u = Q.front();

        for(int i = 0; i < n; i++)
        {
            // 隣接点を全て検索する
            int v = next(u);

            if( v == INV )
            {
                // 隣接点が無くなったらキューから削除して, 処理終了
                Q.pop();
                break;
            }

            if( ary_visit[v] == NO
                && ary_graph[u][v] == EXIST )
            {
                // 訪問済み
                ary_visit[v] = YES;

                Q.push(v);
                vertex_distance[v] = vertex_distance[u] + 1;
            }
        }
    }

    return;
}

C++: #include <iostream>
#include <list>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <algorithm>
#include <cmath>
#include <string>
using namespace std;
typedef long long lli;
typedef vector<lli> vll;
typedef vector<bool> vbl;
typedef vector<vector<lli> > mat;
typedef vector<vector<bool> > matb;
typedef vector<string> vst;
typedef pair<lli,lli> pll;
typedef pair<double,double> pdd;

lli n;
mat g;

lli u,k,v;

queue<lli> q;
queue<lli> d;
vbl vis;
vll ans;


int main(){
    cin >> n;
    g = mat(n+1);
    vis = vbl(n+1);
    ans = vll(n+1);
    for(lli i = 0;i < n;i++){
        cin >> u >> k;
        for(lli j = 0;j < k;j++){
            cin >> v;
            g[u].push_back(v);
        }
    }
    q.push(1);
    d.push(0);
    while(!q.empty()){
        lli p = q.front();
        lli r = d.front();
        q.pop();
        d.pop();
        if(vis[p]) continue;
        vis[p] = true;
        ans[p] = r;
        for(lli i = 0;i < g[p].size();i++){
            if(!vis[g[p][i]]) q.push(g[p][i]),d.push(r+1);
        }
    }
    for(lli i = 1;i <= n;i++) cout << i << " " << ans[i] << endl;
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

int main() {
  int n;
  cin >> n;

  vector<vector<int>> M(n, vector<int>(n));
  for (int i = 0; i < n; i++) {
    int node;
    int d;
    cin >> node >> d;
    node--;

    for (int j = 0; j < d; j++) {
      int tmp;
      cin >> tmp;
      tmp--;
      M[i][tmp] = 1;
    }
  }

  vector<int> res(n, -1);
  vector<int> e(n);
  res[0] = 0;

  queue<int> q;
  q.push(0);

  while (!q.empty()) {
    int num = q.front();
    q.pop();

    int cnt = res[num] + 1;

    for (int i = 0; i < M[num].size(); i++) {
      if (M[num][i] == 0) { continue; }
      if (e[i] == 1) { continue; }
      q.push(i);
      e[i]   = 1;
      res[i] = cnt;
    }
  }
  res[0] = 0;

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

C++: #include<bits/stdc++.h>
#include<string>
#include<cctype>
#include<cmath>
#include<queue> 
#define rep(i,n) for(int i=0;i<(n);i++)
using namespace std;
 
int main(){
  queue <int> q1;
  int n,i,j;
  cin >> n;
  int d[n][n];
  rep(i,n){
    rep(j,n){
      if(i==j){
        d[i][j]=0;
      }else{
       d[i][j]=100000;
      }
    }
  }
  rep(i,n){
    int u,k;
    cin >> u >> k;
    q1.push(u);
    if(k>0){
     int v[k];
     rep(j,k){
       cin >> v[j];
       q1.push(v[j]);
     }
     int f = q1.front()-1;
     q1.pop();
     rep(i,k){
       int e=q1.front()-1;
       d[f][e]=1;
       q1.pop();
     }
    }else{
     q1.pop();
    }
  }

  rep(i,n){
    for(j=2;j<n;j++){
    d[0][i]=min(d[0][i],d[0][j]+d[j][i]);
    }
  }
 
 rep(i,n){
   cout << i+1 << ' ' <<d[0][i] << endl;
 }
 
  return 0;
}