Go: package main

/*
グラフの表現 隣接行列による表現
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		g[i] = make([]int, n+1)
		ints := eGetInts(scanner)
		num := ints[0]
		for j := 0; j < ints[1]; j++ {
			g[num][ints[j+2]] = 1
		}
	}
	dist := make([]int, n+1)
	for i := 0; i < len(dist); i++ {
		dist[i] = -1
	}
	q := []int{}

	// 訪問する
	q = append(q, 1)
	dist[1] = 0

	// キューが空でない限り
	for len(q) > 0 {
		// 先頭を取り出す
		top := 0
		top, q = q[0], q[1:]
		// 隣接マスを入れる.
		for i := 1; i < n+1; i++ {
			// 辺がある
			if g[top][i] == 1 {
				if dist[i] == -1 {
					// 訪問済みでなければ
					q = append(q, i)
					dist[i] = dist[top] + 1
				}
			}
		}
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, dist[i])
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

C++: #include <iostream>
#include <fstream>
#include <string>
#include <cmath>
#include <vector>
#include <algorithm>
#include <functional>
#include <cstdio>
#include <cstdlib>
#include <iomanip>
#include <cctype>
#include <bits/stdc++.h>
#include <queue>

using namespace std;
// for loop
#define F(i, L, R) for(long i = L; i < R; i++)
#define FE(i, L, R) for(long i = L; i <= R; i++)
// for (reversed)
#define FR(i, L, R) for(long i = L; i > R; i--)
#define FRE(i, L, R) for(long i = L; i >= R; i--)

// data types
#define Int long
#define ul unsigned long
#define ll long long
#define ull unsigned long long
#define ui unsigned int
#define us unsigned shoft

// vectors
typedef vector<int> vi;
typedef vector<long> vl;
typedef vector<vi> vvi;
typedef pair<int, int> ii;
#define ALL(c) (c).begin(),(c).end()
#define last(vec) vec.size()-1
#define lastEle(vec) vec[last(vec)]
#define pb push_back
#define InputV(a, n) F(i,0,n){long l; cin >> l; a.pb(l);}

// debug
#define DBG(vari) cerr<<#vari<<" = "<<(vari)<<endl;
#define printA(a, L, R) FE(i, L, R) cout << a[i] << (i==R?'\n':' ')
#define printAF(a, L) printA(a, 0, L-1)
#define printV(a) printA(a, 0, a.size()-1)

// utils
#define char2int(c) (c-'0')
#define bit(x, i) (x&(1<<i))
#define space ' '
#define PI 3.14159265358979323

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;
}

void printM(vector<vector<int> > &vec, long height, long width){
    F(i, 0, height){
        F(j, 0, width){
            cout << vec[i][j] << space;
        }
        cout << endl;
    }
}

vector<int> seen;
vector<int> done;
vector<int> cost;
int timestamp;

// Graph: グラフを表した隣接リスト
// v: 何番目のノードを訪問するのか
void dfs(vector<vector<int> > &Graph, int v){
    timestamp++;
    seen[v] = timestamp; //訪問済みにする

    // 隣接するノードを再帰的に訪問
    for(int next_v = 0; next_v < Graph[v].size();next_v++) {
        if(seen[Graph[v][next_v]] != -1) continue;
        dfs(Graph, Graph[v][next_v]);
    }
    // 出るときの時間が増える
    timestamp++;
    done[v] = timestamp; // 隣接ノードを全て調べ終えた
}

queue<int> que;
vector<long> dist;
// v: 何番目の頂点を訪問しているのか
void bfd(vector<vector<int> > &Graph, int v){
    done[v] = timestamp;

    for(int next_v = 0; next_v < Graph[v].size();next_v++){
        if(seen[Graph[v][next_v]] == -1){
            dist[Graph[v][next_v]] = dist[v] + 1;
            seen[Graph[v][next_v]] = timestamp;
            que.push(Graph[v][next_v]);
        }else{
            dist[Graph[v][next_v]] = min(dist[Graph[v][next_v]], dist[v] + 1);
        }
    }
}

#define TST 0
int main() {
#if TST==1
    ifstream in ("input.txt");
    cin.rdbuf(in.rdbuf());
#endif
    int n;
    cin >> n;
    vvi Graph;
    Graph.resize(n);
    F(i, 0, n){
        int id;
        cin >> id;
        int k;
        cin >> k;
        vi tmp;
        tmp.resize(k);
        F(j, 0, k){
           cin >> tmp[j]; 
           tmp[j]--;
        }
        Graph[i] = tmp;
    }
    seen.assign(n, -1);
    done.assign(n, -1);
    dist.assign(n, -1);
    que.push(0);
    seen[0] = 0;
    dist[0] = 0;
    while(!que.empty()){
       timestamp++;
       int front = que.front();
       bfd(Graph, front);
       que.pop();
    }

    F(i, 0, n){
        cout << i+1 << space << dist[i] << endl;;
    }

#if TST==1
#endif
}

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

#define INFTY 100000

void bfs(int s, vector<vector<int>> &M) {
    int n = M.size();
    queue<int> q;
    q.push(s);

    int d[n];
    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 << " ";
        if (d[i] == INFTY)
            cout << -1;
        else
        {
            cout << d[i];
        }
        cout << endl;
    }
}

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

    vector<vector<int>> M(n, vector<int>(n, 0));
    int u, k, v;
    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, M);
}