Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	n := len(list)
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list[0 : n-1] {
		buf.Write([]byte(fmt.Sprintf("%d ", v)))
	}
	buf.Write([]byte(fmt.Sprintf("%d\n", list[n-1])))
	buf.Flush()
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

//solve
const INFTY = (1 << 21)
const MAX = 100
const WHITE = 0
const GRAY = 1
const BLACK = 2

var time, n int

//隣接行列
var M [MAX][MAX]int

//d[i]: 頂点1から頂点iまでの距離
var color, d [MAX]int

func bfs(s int) {
	var q []int
	q = append(q, s)
	for i := 0; i < n; i++ {
		d[i] = INFTY
	}
	//sは開始点なので、0をいれる
	d[s] = 0

	//キューが空になるまで、以下を繰り返す
	for len(q) > 0 {
		u := q[0]
		q = q[1:]
		for v := 0; v < n; v++ {
			if M[u][v] == 0 {
				continue
			}
			if d[v] != INFTY {
				continue
			}
			d[v] = d[u] + 1
			q = append(q, v)
		}
	}

	for i := 0; i < n; i++ {
		fmt.Printf("%d ", i+1)
		if d[i] == INFTY {
			fmt.Printf("%d\n", -1)
		} else {
			fmt.Printf("%d\n", d[i])
		}
	}
}

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 0; i < n; i++ {
		u, k := nextInt(), nextInt()
		M[u-1][u-1] = 0

		//fmt.Println(u, k)
		if k > 0 {
			for j := 0; j < k; j++ {

				v := nextInt()
				M[u-1][v-1] = 1

			}
		}

	}

	bfs(0)

}

C++: #include <bits/stdc++.h>
#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;
template<class T> inline bool chmax(T &a, T b) { if (a<b) {a=b; return 1;} return 0;}
template<class T> inline bool chmin(T &a, T b) { if (b<a) {a=b; return 1;} return 0;}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    int n;
    cin >> n;
    vector<vector<int>> to(n);
    rep(i, n) {
        int u, k;
        cin >> u >> k;
        u--;
        rep(j, k) {
            int v;
            cin >> v;
            to[u].push_back(--v);
        }
    }

    queue<int> q;
    vector<int> dist(n, -1);
    q.push(0);
    dist[0] = 0;
    
    while (!q.empty()) {
        int v = q.front();
        q.pop();
        for (int i = 0; i < to[v].size(); ++i) {
            int nv = to[v][i];
            if (dist[nv] >= 0) continue;
            q.push(nv);
            dist[nv] = dist[v] + 1;
        }
    }

    rep(i, n) cout << i+1 << " " << dist[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;
}

C++: #include <iostream>
#include <algorithm>
#include <map>
#include <vector>
#include <string>
#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; 
}

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;
}

C++: #include <algorithm>
#include <deque>
#include <iostream>
#include <map>
#include <sstream>
#include <vector>

using namespace std;

deque<int> to_visit;
int t = 1;

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

  vector<bool> visited(n + 1, false);
  vector<int> dist(n + 1, -1);
  vector<vector<int>> V(n + 1);

  cin.ignore();

  for (string line; getline(cin, line);) {
    istringstream is{line};
    int id, n_nbrs, nbr;
    is >> id >> n_nbrs;
    vector<int> out_nbrs;
    while (is >> nbr)
      out_nbrs.push_back(nbr);
    V[id] = out_nbrs;
  }

  to_visit.push_back(1);
  dist[1] = 0;
  while (!to_visit.empty()) {
    if (visited[to_visit.front()]) {
      to_visit.pop_front();
      continue;
    }
    int curr = to_visit.front();
    to_visit.pop_front();
    visited[curr] = true;
    for (auto nbr : V[curr]) {
      if (dist[nbr] == -1)
        dist[nbr] = dist[curr] + 1;
      to_visit.push_back(nbr);
    }
  }

  for (int i = 1; i < V.size(); ++i) {
    cout << i << " " << dist[i] << endl;
  }
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <stdio.h>
#include <cmath>
#include <map>
#include <queue>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main() {
  int n;
  cin >> n;
  vector<vector<int>> Garph(n);
  rep(i, n) {
    int u, k;
    cin >> u >> k;
    rep(j, k) {
      int v;
      cin >> v;
      Garph[u-1].push_back(v-1);
    }
  }
  vector<int> dist(n, -1);
  queue<int> que;
  dist[0] = 0;
  que.push(0);
  while(!que.empty()) {
    int v = que.front();
    que.pop();
    for(auto next_v : Garph[v]) {
      if(dist[next_v] != -1) { continue;}
      dist[next_v] = dist[v] + 1;
      que.push(next_v);
    }
  }
  for(int i = 0; i < n; i++) {
    printf("%d %d\n", i+1, dist[i]);
  }
  return 0;
}