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++: /*
?????????: Graph I - Breadth First Search
URL: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_C
?????°
19:08 ??°?????????????????????????????£??¨??????????????????????????§???????????????????????£?????????
19:08 ???????????\????????\????????°??????????????????????¢????
19:09 ????????°???????????????????§£
19:13 ??¨???????????????????????£???
19:19 BFS????¨???¶???????¶??????????????????§??¨?????????????????????????????????
19:28 ???????????????????§?????????????????????£????????§????????????????????????????????????????????§????????????????????£????????????
*/
#include <iostream>
#include <vector>
#include <set>
#include <queue>
#define INF 114514
using namespace std;

int main()
{
	int n; cin>>n;
	vector< set<int> > graphdat(n+1);  
	for(int i=0;i<n;i++){
		int u; int k; cin >> u >> k;
		set<int> v;
		for(int j=0;j<k;j++){
			int tmp;
			cin >> tmp;
			v.insert(tmp);
		}
		graphdat[u] = v;
	}

	vector<int> distance(n+1);
	distance[1] = 0;
	for(int i=2;i<=n;i++){
		distance[i] = INF;
	}

	queue<int> Q;
	Q.push(1);

	while(!Q.empty()) {
		int cur = Q.front();
		Q.pop(); // pop?????????????????????????????¨?¬???\??§??????
		for(int dest=1; dest<=n; dest++) {
			if(graphdat[cur].find(dest) != graphdat[cur].end()) { // ??????????????????
				if(distance[dest] > distance[cur] + 1) { // ??´??°??§????????????
					distance[dest] = distance[cur] + 1;
					Q.push(dest);
				}
			}
		}
	}

	for(int i=1;i<=n;i++){
		cout << i << " " << distance[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);

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;
}

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;
    }
}

C++: #include<stdio.h>


#define MAX 101
#define WHITE 2
#define GRAY 1
#define BLACK 0

int col[MAX], d[MAX], a[MAX][MAX]; 
 
int n, h= 0, t = 0;


int Que[MAX];


/*Qの操作*/
 int Dequeque(){
  h++;
  return Que[h - 1];
}
void Enqueque(int b){
  Que[t] = b;
  t++;
}

 
void BFS(int s){
  int i, u;
  for(i = 1; i < n+1; i++){
      col[i] = WHITE;


      d[i] = -1;
  }
  d[s] = 0;
  

  col[s] = GRAY;
  
  Enqueque(s);
 
  while(h != t){
    u = Dequeque();
    for(i = 1; i <= n; i++){
      if((col[i] == WHITE) && (a[u][i] == 1)){


    col[i] = GRAY;
    d[i] = d[u] + 1;
    Enqueque(i);
      }
    }
   

    col[u] = BLACK;
  }
}
 

  
int main(){
 
  scanf("%d", &n);
 
  int i, u, j,y=1,e;



  /*配列の初期化*/
  for(i = 1; i < n+1; i++){
    for(j = 1; j < n+1; j++){
     

 a[i][j] = 0;

    }
  }

  int x; 
  for(i = 1; i < n+1; i++){

    scanf("%d%d",&u,&e);
    for(j = 1; j <= e; j++){
      scanf("%d", &x);
      a[i][x] = 1;
    }
  }
 
  BFS(y);
   
  for(i = 1; i < n+1; i++){
    printf("%d ", i);
    printf("%d\n", d[i]);
  }
  return 0;
}

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

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    vector<int> G[n];
    for(int i = 0; i < n; i++){
        int p, k;
        cin >> p >> k;
        for(int j = 0; j < k; j++){
            int a;
            cin >> a;
            G[p - 1].push_back(a - 1);
        }
    }

    vector<int> D(n, 1e9);
    D[0] = 0;
    queue<int> q;
    q.push(0);

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

        for(int i = 0; i < G[now].size(); i++){
            int to = G[now][i];
            if(D[now] + 1 < D[to]){
                D[to] = D[now] + 1;
                q.push(to);
            }
        }
    }

    for(int i = 0; i < n; i++){
        cout << i + 1 << ' ' << (D[i] == 1e9 ? -1 : D[i]) << endl;
    }

    return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;
typedef long long ll;

#define INF (long long)(1e9+7)
#define REP(i,n) for(ll i = 0; i < n; i++)
#define REP1(i,n) for(ll i = 1; i <= n; i++)

using Graph = vector<vector<int>>;


int main(void)
{
  int n;
  cin >> n;
  Graph G(n);
  int u, k;
  REP(j, n) {
    cin >> u >> k;
    u--;
    REP(i, k) {
      int v;
      cin >> v;
      v--;
      G[u].push_back(v);
      //      G[v].push_back(u);
    }
  }

  vector<int> dist(n, -1);
  queue<int> que;

  dist[0] = 0;
  que.push(0);

  while(!que.empty()) {
    int v = que.front(); que.pop();

    for(int nv : G[v]) {
      if(dist[nv] != -1) continue;

      dist[nv] = dist[v] + 1;
      que.push(nv);
    }
  }
  REP(i, n) cout << i + 1 << " " << dist[i] << endl;

}