Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)

	g := make([][]int, n+1)
	d := make([]int, n+1)
	for i := 0; i < n; i++ {
		var u,k int
		fmt.Scan(&u)
		fmt.Scan(&k)
		g[u] = make([]int, k)
		for j := 0; j < k; j++ {
			fmt.Scan(&g[u][j])
		}

		d[i+1] = -1
	}

	q := [][]int{}
	q = append(q, []int{1, 0})
	for len(q) > 0 {
		pop := q[0]
		if len(q) > 1 {
			q = q[1:]
		} else {
			q = [][]int{}
		}
		if d[pop[0]] >= 0 {
			continue
		}
		d[pop[0]] = pop[1]

		for j := 0; j < len(g[pop[0]]); j++ {
			q = append(q, []int{g[pop[0]][j], pop[1]+1})
		}
	}

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

C++: #include <iostream>
#include<stdio.h>
#include<stack>
#include<queue>

#define MAX 100
#define WHITE 1
#define GRAY 2
#define BLACK 3

using namespace std;

int color[MAX], d[MAX], f[MAX];
int n, A[MAX][MAX];
int nt[MAX];
int dis[MAX]; //?????¶???????????????????????????
int tt = 0;

void dfs_visit_1(int u) { //???????????°
    color[u] = GRAY;
    d[u] = ++tt;
    for(int v = 0; v < n; v++) {
        if(A[u][v] == 0) continue;
        if(color[v] == WHITE) dfs_visit_1(v);
    }
    color[u] = BLACK;
    f[u] = ++tt;
}

int next(int u) {
    for(int v = nt[u]; v < n; v++) {
        nt[u] = v+1;
        if(A[u][v] == 1) return v;
    }
    return -1;
}

void dfs_visit_2(int u) { //????????°
    for(int i = 0; i < n; i++) nt[i] = 0;
    color[u] = GRAY;
    d[u] = ++tt;
    stack<int> S;
    S.push(u);

    while(!S.empty()) {
        int u = S.top();
        int v = next(u);
        if(v != -1) {
            if(color[v] == WHITE) {
                color[v] = GRAY;
                d[v] = ++tt;
                S.push(v);
            }
        }else {
            S.pop();
            color[u] = BLACK;
            f[u] = ++tt;
        }
    }
}

void dfs() { // ?????????????????°
    for(int i = 0; i < n; i++) {
        color[i] = WHITE;
        nt[i] = 0;
    }
    tt = 0;
    for(int i = 0; i < n; i++) {
        if(color[i] == WHITE) dfs_visit_2(i);
    }
    for(int i = 0; i < n; i++) {
        printf("%d %d %d\n", i+1, d[i], f[i]);
    }
}

void bfs(int u) {
    dis[0] = 0;
    for(int i = 1; i < n; i++) dis[i] = -1;
    queue<int> Q;
    Q.push(u);
    while(!Q.empty()) {
      int u = Q.front();
      Q.pop();
        for(int v = 0; v < n; v++) {
            if(A[u][v] == 1 && dis[v] == -1) {
                Q.push(v);
                dis[v] = dis[u] + 1;
            }
        }
    }

    for(int i = 0; i < n; i++) {
        printf("%d %d\n", i+1, dis[i]);
    }
}

int main()
{
    int u, k, v;
    scanf("%d",&n);

    for(int i = 0; i < n; i++) {
        scanf("%d%d", &u, &k);
        for(int j = 0; j < k; j++) {
            scanf("%d", &v);
            A[u-1][v-1] = 1;
        }
    }

    /*
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            printf("%d", A[i][j]);
            if(j != n-1) printf(" ");
        }
        printf("\n");
    }
    */
    //dfs();
    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;
    for(int j=0;j<k;j++){
      cin>>v;
      v--;
      m[u][v]=1;
    }
  }

  bfs(0);

  return 0;
}

C++: //Breadth First Search (?????????) Algorithm
#include<iostream>
#include<queue>
#define WH 0
#define GR 1
#define BL 2
#define INF 2000000
void bfs(int);
void init(void);
int n, *color, **M, *d;
std::queue<int> Q;
int main(){
  std::cin>>n;
  color=new int[n], d=new int[n], M=new int*[n];
  for(int i=0, u, k;i<n;i++){
    M[i]=new int[n];
    color[i]=WH, d[i]=INF;
    for(int j=0;j<n;j++) M[i][j]=0;
    std::cin>>u>>k;
    for(int j=0, v;j<k;j++){
      std::cin>>v;
      M[u-1][v-1]=1;
    }
  }
  bfs(0);
  for(int i=0;i<n;i++) std::cout<<i+1<<" "<<d[i]<<std::endl;
  delete color;
  delete d;
  for(int i=0;i<n;i++) delete M[i];
  delete M;
  return 0;
}

void bfs(int s){
  color[s]=GR, d[s]=0;
  Q.push(s);
  while(!Q.empty()){
    int u=Q.front();
    Q.pop();
    for(int i=0;i<n;i++){
      if(M[u][i]&&color[i]==WH){
        color[i]=GR, d[i]=d[u]+1;
        Q.push(i);
      }
    }
    color[u]=BL;
  }
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <deque>
#include <queue>
#include <list>
#include <stack>
#include <string>
#include <tuple>
#include <functional>
#include <numeric>
#include <cmath>
#include <iomanip>
#include <map>
#include <random>
#include <cstdlib>
#define Loop(i, n) for(int i = 0; i < (int)n; i++)
#define Loop1(i, n) for(int i = 1; i <= (int)n; i++)
#define Loopr(i, n) for(int i = (int)n - 1; i >= 0; i--)
#define Loopr1(i, n) for(int i = (int)n; i >= 1; i--)
using namespace std;
typedef long long int ll;

vector<int> V[105];
queue<int> Q;
vector<int> color(105, 1), d(105, -1);

int main() {
	int n;
	cin >> n;
	Loop(i, n) {
		int u, k;
		cin >> u >> k;
		Loop(j, k) {
			int v;
			cin >> v;
			V[u].push_back(v);
		}
	}
	//
	Q.push(1);
	color[1] = 2;
	d[1] = 0;
	while (Q.size() > 0) {
		int u = Q.front();
		Q.pop();
		Loop(i, V[u].size()) {
			if (color[V[u][i]] == 1) {
				Q.push(V[u][i]);
				color[V[u][i]] = 2;
				d[V[u][i]] = d[u] + 1;
			}
		}
	}
	Loop1(i, n) {
		cout << i << " " << d[i] << endl;
	}
	return 0;
}

C++: //
//  main.cpp
//  619
//
//  Created by 8595198919 on 14/06/16.
//  Copyright (c) 2014年 8595198919. All rights reserved.
//

#include <iostream>
#include <cstdio>
#include <queue>
#define rep(i,n) for(int i = 0;i<n;i++)
using namespace std;

int dist[105];
queue<int> que;
vector<int> G[105];
int main(int argc, const char * argv[])
{
    int n;
    cin >> n;
    for(int i = 0;i <= n;i++) {
        dist[i]=-1;
    }
    for(int i = 0;i < n;i++){
        int u,k;
        int to;
        scanf("%d %d",&u,&k);
        for(int j=0;j<k;j++){
            scanf("%d",&to);
            G[u].push_back(to);
        }
    }
    que.push(1);
    dist[1]=0;
    while(!que.empty()){
        int now = que.front();
        que.pop();
        int d = dist[now];
        rep(i,G[now].size()){
            if(dist[G[now][i]]==-1){
                dist[G[now][i]]=d+1;
                que.push(G[now][i]);
            }
        }
    }
    for(int i = 1;i <= n;i++) {
        cout <<i <<" " << dist[i]<<endl;
    }
}

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

int main(){
    int n; cin >> n;
    Graph G(n);
    for(int i = 0; i < n; i++){
        int u, k; cin >> u >> k;
        for(int j = 0; j < k; j++){
            int a; cin >> a;
            G.at(u - 1).push_back(a);
        }
    }
    vector<int> dist(n, -1);
    dist[0] = 0;
    queue<int> que;
    que.push(1);
    while(!(que.empty())){
        int v = que.front();
        que.pop();
        for(auto nv : G.at(v - 1)){
            if(dist[nv - 1] != -1){
                continue;
            }
            else{
                que.push(nv);
                dist[nv - 1] = dist[v - 1] + 1;
            }
        }
    }
    for(int i = 1; i <= n; i++){
        cout << i << " " << dist[i - 1] << endl;
    }
}