Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	nodes := make([]Node, n)

	for i := 0; i < n; i++ {
		nodes[i].list = make([]int, 0)
		nodes[i].d = -1
	}

	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		u--
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			v--
			nodes[u].list = append(nodes[u].list, v)
		}
	}

	queue := make([]int, n)
	queue[0] = 0
	nodes[0].d = 0
	d := 0
	i, j := 0, 1
	for i < j {
		d++
		prev := j
		for i < prev {
			for k, l := 0, len(nodes[queue[i]].list); k < l && i < n; k++ {
				if nodes[nodes[queue[i]].list[k]].d != -1 {
					continue
				}
				nodes[nodes[queue[i]].list[k]].d = d
				queue[j] = nodes[queue[i]].list[k]
				j++
			}
			i++
		}
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i+1, nodes[i].d))
	}

	writer.Flush()
}

// Node ...
type Node struct {
	list []int
	d    int
}

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

int G[110][110];
bool seen[110];
int d[110];
int N;

struct MyQueue{
    int num[110];
    int head = 0;
    int tail = 0;

    void enqueue( int n ){
        num[tail++] = n;
    }

    int dequeue(){
        return num[head++];
    }

    bool empty(){
        return head == tail;
    }
};

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

    MyQueue que;
    que.enqueue( 0 );
    seen[0] = 1;
    while( !que.empty() ){
        int u = que.dequeue();
        for( int v = 0; v < N; v++ ){
            if( G[u][v] && !seen[v] ){
                que.enqueue( v );
                d[v] = d[u] + 1;
                seen[v] = 1;
            }
        }
    }

    for( int i = 1; i < N; i++ ){
        if( d[i] == 0 ) d[i] = -1;
    }

    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;
}

C++: #include <iostream> // cout, endl, cin
#include <string> // string, to_string, stoi
#include <vector> // vector
#include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
#include <utility> // pair, make_pair
#include <tuple> // tuple, make_tuple
#include <cstdint> // int64_t, int*_t
#include <cstdio> // printf
#include <map> // map
#include <queue> // queue, priority_queue
#include <set> // set
#include <stack> // stack
#include <deque> // deque
#include <unordered_map> // unordered_map
#include <iomanip>
#include <unordered_set> // unordered_set
#include <bitset> // bitset
#include <cctype> // isupper, islower, isdigit, toupper, tolower
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
using namespace std;
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
const int INF = 1000000000;
const int MOD = 1000000007;

typedef pair<int, int> P;
int myAbs(int num) {
    if (num > 0)
        return num;
    else
        return -num;
}

long long gcd(long long a, long long b) {
    if (b == 0) return a;
    else return gcd(b, a % b);
}
long long lcm(long long a, long long b) {
    return a * b / gcd(a, b);
}

using Graph = vector<vector<int>>;
//再帰とかグラフを使うときは予めNの最大値のグローバル配列を取っておく
int N;
bool E[101][101];
vector<bool> seen;
typedef pair<int, int> P;
int D[101];
//頂点状態を表すcolor[]において、0は未訪問、1は訪問中、2は完了を表す。
int color[101];
int find_time = 0;

void bfs(int start) {
    //全頂点を未訪問にして距離も初期化(INF)
    for (int i = 0; i < 101; i++) D[i] = -1;
    queue<int> Q;
    //最初の頂点をキューに入れる
    Q.push(start);
    int v;
    //最初の頂点は距離0
    D[start] = 0;
    //キューが空になるまで探索
    while (!Q.empty()) {
        v = Q.front();
        Q.pop();
        for (int i = 1; i <= N; i++) {
            //今訪問している頂点vから辺があるか&&すでに訪問済み(距離がINFではない)を確認
            if (!E[v][i]) continue;
            if (D[i] != -1) continue;
            //未訪問かつ辺があったなら元の頂点の距離に1を足す
            D[i] = D[v] + 1;
            //発見した頂点をキューに入れて再度探索
            Q.push(i);
        }
    }
    for (int i = 1; i <= N; i++) {
        cout << i << " " << D[i] << endl;
    }
}

int main() {
    cin >> N;
    int u, k,v;
    //頂点を1から入力(0ではなく)
    //辺の有無をbool E[][]で管理
    for (int i = 0; i < N; i++) {
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            cin >> v;
            E[u][v] = true;
        }
    }
    //探索開始頂点を引数にして開始
    bfs(1);

}

C++: #include <cstdio>
#include <cstring>
#include <queue>

using namespace std;
int g[101][101], d[101];
bool vis[101];
int dis = 0, n;

void bfs(int u)
{
  queue<int> Q;
  Q.push(u);
  vis[u] = true;
  d[u] = 0;
  while (!Q.empty())
  {
    int tmp = Q.front();
    Q.pop();
    for (int i = 0; i < n; i++)
    {
      if (g[tmp][i] != 0 && !vis[i])
      {
        vis[i] = true;
        Q.push(i);
        d[i] = d[tmp] + 1;
      }
    }
  }
}

int main()
{
  memset(g, 0, sizeof(g));
  memset(d, -1, sizeof(d));
  memset(vis, false, sizeof(vis));
  scanf("%d", &n);
  for (int i = 0; i < n; i++)
  {
    int u, adj_num;
    scanf("%d%d", &u, &adj_num);
    while (adj_num--)
    {
      int v;
      scanf("%d", &v);
      g[u - 1][v - 1] = 1;
    }
  }
  bfs(0);
  for (int i = 0; i < n; i++)
  {
    printf("%d %d\n", i + 1, d[i]);
  }
}

C++: #include <cstdio>
#include <iostream>
#include <cmath>
#include <ctype.h>
#include <string>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <map>
#include <queue>
#include <utility>
#include <vector>
#include <set>
#include <list>
#include <cstring>
#include <stack>

using namespace std;

#define mod 1000000007

int main()
{
	int n;
	int graph[101][101] = {};
	cin >> n;
	int ans[101] = {};
	for(int i = 0; i < n; i++){
		ans[i] = -1;
		int u, k;
		cin >> u >> k;
		u--;
		for(int j = 0; j < k; j++){
			int v;
			cin >> v;
			v--;
			graph[u][v] = 1;
		}
	}
	queue<int> qu;
	qu.push(0);
	ans[0] = 0;
	while(!qu.empty()){
		int tmp = qu.front();
		qu.pop();
		for(int i = 0; i < n; i++){
			if(ans[i] == -1 && graph[tmp][i] > 0){
				ans[i] = ans[tmp] + 1;
				qu.push(i);
			}
		}
	}
	for(int i = 0; i < n; i++){
		cout << i + 1 << " " << ans[i] << endl;
	}
}