Go: package main

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

type AdjacentList struct {
	matrix [][]int
}

func NewEmptyAdjacentList(dim int) *AdjacentList {
	matrix := make([][]int, dim)
	for i := 0; i < dim; i++ {
		matrix[i] = make([]int, dim)
	}
	return &AdjacentList{matrix: matrix}
}

func (al *AdjacentList) set(node int, adjacent int) {
	al.matrix[node-1][adjacent-1] = 1
}

func (al *AdjacentList) findAdjacentsFor(node int) []int {
	adjacents := []int{}
	for i, v := range al.matrix[node-1] {
		if v == 1 {
			adjacents = append(adjacents, i+1)
		}
	}
	return adjacents
}

type DistanceList struct {
	list []int
}

func NewDistanceList(dim int) *DistanceList {
	list := make([]int, dim)
	for i := 0; i < dim; i++ {
		list[i] = -1
	}
	return &DistanceList{list: list}
}

func (dl *DistanceList) set(node int, distance int) {
	dl.list[node-1] = distance
}

func (dl *DistanceList) get(node int) int {
	return dl.list[node-1]
}

func (dl *DistanceList) isVisited(node int) bool {
	return dl.list[node-1] >= 0
}

type Position struct {
	node     int
	distance int
}

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

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

	al := NewEmptyAdjacentList(dim)

	for i := 1; i <= dim; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}

		adjacentNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		for j := 0; j < adjacentNum; j++ {
			adjacent, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			al.set(node, adjacent)
		}
	}

	dl := NewDistanceList(dim)

	bfs(al, dl)

	for i := 1; i <= dim; i++ {
		fmt.Printf("%d %d\n", i, dl.get(i))
	}
}

func bfs(al *AdjacentList, dl *DistanceList) {
	stack := []Position{Position{node: 1, distance: 0}}
	for len(stack) > 0 {
		currentPosition := stack[0]
		stack = stack[1:]
		if !dl.isVisited(currentPosition.node) {
			dl.set(currentPosition.node, currentPosition.distance)
		}
		for _, v := range al.findAdjacentsFor(currentPosition.node) {
			if !dl.isVisited(v) {
				stack = append(stack, Position{node: v, distance: currentPosition.distance + 1})
			}
		}
	}
}

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

C++: #include <cstdio>
#include <iostream>
#include <vector>
#include <cstring>
#include <queue>
#include <algorithm>
#include <utility>
#define rep(i,n) for(int i=0; i<(n); ++i)
#define reps(i, s, n) for(int i=(s); i<=(n); ++i)
#define outl(x) cout<< (x) << '\n'
#define fi first
#define se second
#define mkp make_pair

#define INF 0x3f3f3f3f
using namespace std;

int N;
vector <int> G[102];
int far[102];

void slv()
{
   queue <int> que;
   que.push(1);
   memset( far, INF, sizeof(far) );
   far[1] = 0;

   while(!que.empty()){
      const int u = que.front();
      que.pop();
      rep(i, G[u].size()){
         const int next = G[u][i];
         if(far[u] + 1 < far[next]){
            far[next] = far[u] + 1;
            que.push( next );
         }
      }
   }

   reps(i, 1, N){
      cout << i <<  ' ' << ( far[i] == INF ? -1 : far[i] ) << '\n';
   }
   return;
}

signed main()
{
   cin.tie(0), ios::sync_with_stdio(false);
   cin >> N;

   reps(i, 1, N){
      int u, k, a;
      cin >> u >> k;
      while(k--){
         cin >> a;
         G[u].push_back(a);
      }
   }

   slv();
   return (0);
}

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

// 総数を1000000007で割った余り
const long long mod = 1e9 + 7;

using ll  = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define ull unsigned long long
#define ld long double
#define vi vector<int>
#define vll vector<ll>
#define vc vector<char>
#define vs vector<string>
#define vpii vector<pii>
#define vpll vector<pll>

#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; i++)
#define rep1(i, n) for (int i = 1, i##_len = (n); i <= i##_len; i++)
#define repr(i, n) for (int i = ((int)(n)-1); i >= 0; i--)
#define rep1r(i, n) for (int i = ((int)(n)); i >= 1; i--)

#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

#define SORT(v, n) sort(v, v + n);
// #define SORT(v, n) stable_sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define RSORT(x) sort(rall(x));
#define pb push_back
#define mp make_pair

#define INF (1e9)
#define PI (acos(-1))
#define EPS (1e-7)

ull gcd(ull a, ull b) { return b ? gcd(b, a % b) : a; }
ull lcm(ull a, ull b) { return a / gcd(a, b) * b; }

const int N     = 100;
const int INFTY = (1 << 21);

int n, M[N][N];
int d[N];  // 距離で訪問状態(color)を管理する。

void bfs(int s) {
    queue<int> q;  //標準ライブラリのqueueを使用。
    q.push(s);
    rep(i, n) d[i] = INFTY;
    d[s]           = 0;
    int u;
    while (!q.empty()) {
        u = q.front();
        q.pop();
        rep(v, n) {
            if (M[u][v] == 0) continue;
            if (d[v] != INFTY) continue;
            d[v] = d[u] + 1;
            q.push(v);
        }
    }
    rep(i, n) {
        cout << i + 1 << " " << ((d[i] == INFTY) ? (-1) : d[i]) << endl;
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    // cout << fixed << setprecision(5);

    int u, k, v;
    cin >> n;
    rep(i, n) { rep(j, n) M[i][j] = 0; }
    rep(i, n) {
        cin >> u >> k;
        u--;
        rep(j, k) {
            cin >> v;
            v--;
            M[u][v] = 1;
        }
    }

    bfs(0);

    return 0;
}

C++: #include<bits/stdc++.h>
#define INF 10000000
using namespace std;

int z[100],n,w[100];
int a[100][100];

void bfs(){
  int m;
  z[0]=0;
  queue<int> q;
  q.push(0);
  while(!q.empty()){
    m=q.front();
    q.pop();
    if(w[m]==1) continue;
    w[m]=1;
    for(int i=0;i<n;i++){
      if(a[m][i]==1){
	q.push(i);
	z[i]=min(z[i],z[m]+1);
      }
    }
  }
}


int main(){
  int p,x;
  for(int i=0;i<100;i++){
    z[i]=w[i]=INF;
    for(int j=0;j<100;j++) a[i][j]=0;
  }
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>p>>p;
    for(int j=0;j<p;j++){
      cin>>x;
      a[i][x-1]=1;
    }
  }
  bfs();
  for(int i=0;i<n;i++){
    if(z[i]!=INF) cout<<i+1<<" "<<z[i]<<endl;
    else cout<<i+1<<" "<<-1<<endl;
  }
  return 0;
}

C++: #include<iostream>
#include<vector>
#include<queue>
#include<algorithm>
using namespace std;
int main()
{
  queue<int> Q;
  int n,u,k,vv,cur,dst;
  cin >> n;
  vector<int> D(n,-1);
  vector< vector<int> > v(n);
  for(int i = 0;i < n;++i){
    cin >> u >> k;
    for(int j = 0;j < k;++j){
      cin >> vv;
      v[u - 1].push_back(vv);
    }
    sort(v[u - 1].begin(),v[u - 1].end());
  }
  D[0] = 0;
  Q.push(1);
  while(!Q.empty()){
    cur = Q.front();
    Q.pop();
    for(int i = 0;i < v[cur - 1].size();++i){
      dst = v[cur - 1][i];
      if(D[dst - 1] == -1) D[dst - 1] = D[cur - 1] + 1;
      Q.push(dst);
    }
  }
  for(int i = 0;i < n;++i)
    cout << i + 1 << " " << D[i] << endl;
}

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