Go: package main

import "fmt"

type container struct {
	data []int
}

func (c *container) queue(v int) {
	c.data = append(c.data, v)
}
func (c *container) dequeue(p *int) bool {
	if p == nil || len(c.data) == 0 {
		return false
	}
	*p = c.data[0]
	c.data = c.data[1:len(c.data)]
	return true
}

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

	var q container
	d[1] = 0
	q.queue(1)

for len(q.data) > 0  { // 幅優先探索
		var v int
		q.dequeue(&v)
		for i := 0; i < len(g[v]); i++ {
			nv := g[v][i]
		if d[nv] == -1 { // 未訪問
				q.queue(nv)
				d[nv] = d[v] + 1
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d\n", i, d[i])
	}
}

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <stdlib.h>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
#define max 101
#define INF 200000000
#define WHITE 0
#define GRAY -1
#define BLACK 1
int n,color[max],d[max];
int varry[max][max];
void bfs(int s){
  queue<int>q;
  int u;
  for(int i=0;i<=n;i++){
    d[i]=INF;
  }
  color[s]=GRAY;
  d[s]=0;
  q.push(s);
  while(!q.empty()){
    u=q.front();
    q.pop();
    for(int i=1;i<varry[u][0]+1;i++){
      if(color[varry[u][i]]==WHITE){
	color[varry[u][i]]=GRAY;
	d[varry[u][i]]=d[u]+1;
	q.push(varry[u][i]);
      }
    }
    color[u]=BLACK;
  }

}
int main(){
  int n,u;
  cin>>n;
  for(int k=0;k<n;k++){
    cin>>u;
    cin>>varry[u][0];
    for(int i=0;i<varry[u][0];i++)
      cin>>varry[u][i+1];
  }
  bfs(1);
  for(int i=1;i<=n;i++)
    cout<<i<<" "<<d[i]<<endl;


  return 0;
}

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


int map_max;
int map[110][110];
int rows;
int cols[110];
int howfar[110];
int far;
int visited[110];

void get_map();
void print_map();
int search(int node, int far);
void print_result();
void check_result();

int main()
{

  get_map();
  //print_map();
  search(1, 0);
  check_result();
  print_result();
  return 0;
}

void check_result()
{
  for(int i=1;i<map_max;i++)
    {
      if(howfar[i]==0)
	{
	  howfar[i]=-1;
	}
    }
}

void print_result()
{
  for(int i=0;i<map_max;i++)
    {
      std::cout << i+1 << " " << howfar[i] << std::endl;
    }
}

void get_map()
{

  int k;
  scanf("%d", &map_max);//<100

  for(int i=0;i<map_max;i++)
    {
      scanf("%d", &k);
      scanf("%d", &cols[i]);
      for(int j=0;j<cols[i];j++)
	{
	  map[i][j]=0;
	  scanf("%d", &map[i][j]);
	}
    }

  
  return ;
}

void print_map()
{
  for(int i=0;i<map_max;i++)
    {
      for(int j=0;j<cols[i];j++)
	{
	  printf("%d", map[i][j]);
	}
      puts("");
    }
return ;
}


int search(int node, int far)
{
  if(visited[node-1] == 1)//searched
    {
      if(howfar[node-1]>far)
	{
	  howfar[node-1]=far;
	}
      return -1;
    }
  else
    {
      howfar[node-1]=far;
      //for(int i=0;i<cols[node-1];i++)
      //{
      //  //if(map[node-1][i]!=0)
      //  {
      //  search(map[node-1][i], far+1);
      //  }
      //}
      visited[node-1]=1;
      //return -1;
    }

   for(int i=0;i<cols[node-1];i++)
    {
      //if(map[node-1][i]!=0)
  	{
  	  search(map[node-1][i], howfar[node-1]+1);
  	}
    }
  return -1;
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define loop(i,a,b) for(i=a;i<b;i++)
#define rloop(i,a,b) for(i=a;i>=b;i--)
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
const int inf=1000000001;
const ll INF=1e16;
#define MOD 1000000007
#define mod 1000000009
#define pi 3.14159265358979323846
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;
static const int N=101;

int n;
vi d(N,-1),color(N,WHITE);
vii M(N,vi(N,0));

void bfs();
void bfs_visit(int);

int main(){
	int i,j;
	cin>>n;
	int u,k,v;
	loop(i,0,n){
		cin>>u>>k;
		loop(j,0,k){
			cin>>v;
			M[u][v]=1;
		}
	}
	
	bfs();
}

void bfs(){
	int u;
	bfs_visit(1);
	loop(u,1,n+1){
		cout<<u<<" "<<d[u]<<endl;
	}
}

void bfs_visit(int r){
	queue<int> q;
	int v;
	q.push(r);
	d[r]=0;
	while(!q.empty()){
		int u=q.front();
		loop(v,1,n+1){
			if(M[u][v] && color[v]==WHITE){
				q.push(v);
				color[v]=GRAY;
				d[v]=d[u]+1;
			}
		}
		color[u]=BLACK;
		q.pop();
	}
}

C++: #include <iostream>
#include <vector>
#include <queue>

using namespace std;

#define MAX 101

int d[MAX],visited[MAX];
vector<int> G[MAX];
queue<int> Q;

int main(){
  int n; cin >> n;
  for(int i=0;i<n;i++){
    int u,k; cin >> u >> k;
    for(int i=0;i<k;i++){
      int v; cin >> v;
      G[u].push_back(v);
    }
  }
  //bread first search
  for(int i=1;i<=n;i++){
    visited[i]=0;
    d[i]=-1;
  }
  visited[1]=1;
  d[1]=0;
  Q.push(1);
  while(!(Q.empty())){
    int u=Q.front(); Q.pop();
    for(int v=0;v<G[u].size();v++){
      if(visited[G[u][v]]==0){
        visited[G[u][v]]=1;
        d[G[u][v]]=d[u]+1;
        Q.push(G[u][v]);
      }
    }
  }
  for(int i=1;i<=n;i++){
    cout << i << " " << d[i] << endl;
  }
}

C++: #include <iostream>
#include <vector>
#include <cstring>
#include <queue>

using namespace std;

int n;
int g[101][101] = {};
int sp[101] = {};


void bfs(){

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

  while( !q.empty() ){
    int v = q.front(); q.pop();
    for(int i=1; i<=n; i++){
      if(g[v][i] == 1 && sp[i] == -1){
	q.push(i);
	sp[i] = sp[v]+1;
      }
    }
  }
}


int main(){

  memset(g,0,sizeof(g));
  memset(sp,-1,sizeof(sp));
  cin >> n;
  sp[1] = 0;

  for(int i=1; i<=n; i++){
    int u,v,k;
    cin >> u >> k;
    for(int j=0; j<k; j++){
      cin >> v;
      g[u][v] = 1;
    }
  }

  bfs();

  for(int i=1; i<=n; i++)
    cout << i << " " << sp[i] << endl;

}

C++: #include <iostream>
#include<string>
#include<cmath>
#include<algorithm>
#include<cctype>
#include<queue>
#include<stack>
#include<stdio.h>
#include<vector>
#include<set>
#include<map>
#include<array>
#include<iomanip>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
int INF = (1<<29);
int ms[100][100],n;
int d[100];


void dfs(int a){
    rep(i,n){
        d[i]=INF;
    }
    queue<int> q;
    q.push(a);
    d[a]=0;
    while(!q.empty()){
        int b=q.front();q.pop();
        for(int i=0;i<n;i++){
            if(ms[b][i]!=0&&d[i]==INF){
                d[i]=d[b]+1;
                q.push(i);
                
            }
        }
    }
    
    
    
    rep(i,n){
        cout<<i+1<<" "<<(d[i]==INF?-1:d[i])<<endl;
    }
}


int main(){
    cin>>n;
    rep(i,n){
        int a,b,c;
        cin>>a>>b;
        a--;
        rep(j,b){
            cin>>c;
            c--;
            ms[a][c]=1;
        }
    }
    
    dfs(0);
    return 0;

    
}