Go: package main

import (
	"fmt"
	"os"
	"bufio"
	"strconv"
	"container/list"
)

const MaxNode int = 100

var d []int
var A [][]int
var N int
var l *list.List

func bfs(u int) {
	d[u] = 0
	l.PushBack(u)
	for ;l.Len() != 0; {
		u = l.Front().Value.(int)
		l.Remove(l.Front())
		for v:=0; v<N; v++ {
			if A[u][v] == 0 {
				continue
			}
			if d[v] != -1 {
				continue
			}
			d[v] = d[u] + 1
			l.PushBack(v)
		}
	}
}


func nextInt(scanner *bufio.Scanner) int {
	scanner.Scan()
	num, _ := strconv.Atoi(scanner.Text())
	return num
}

func print() {
	for i:=0; i<N; i++ {
		fmt.Printf("%d %d\n", i+1, d[i])
	}
}

func initVariable() {
	d = make([]int, MaxNode)
	A = make([][]int, MaxNode)
	l = list.New()
	for i:=0; i<MaxNode; i++ {
		A[i] = make([]int, MaxNode)
		d[i] = -1
	}
}


func main() {
	initVariable()
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	N = nextInt(scanner)
	for i:=0; i<N; i++ {
		idx := nextInt(scanner)
		cnt := nextInt(scanner)
		for j:=0; j<cnt; j++ {
			node := nextInt(scanner)
			A[idx-1][node-1] = 1 
		}
	}
	bfs(0)
	print()
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n - 1); i >= 0; i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) int(x.size())
#define get_unique(x) x.erase(unique(all(x)), x.end());
typedef long long ll;
typedef complex<double> Complex;
const int INF = 1e9;
const ll MOD = 1e9 + 7;
const ll LINF = 1e18;
template <class T>
bool chmax(T& a, const T& b) {
    if (a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
bool chmin(T& a, const T& b) {
    if (b < a) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
vector<T> make_vec(size_t a) {
    return vector<T>(a);
}
template <class T, class... Ts>
auto make_vec(size_t a, Ts... ts) {
    return vector<decltype(make_vec<T>(ts...))>(a, make_vec<T>(ts...));
}
int main() {
    int n;
    cin >> n;
    vector<vector<int>> g(n);
    rep(i, n) {
        int u, k;
        cin >> u >> k;
        u--;
        rep(j, k) {
            int v;
            cin >> v;
            v--;
            g[u].push_back(v);
        }
    }
    vector<int> d(n, -1);
    queue<int> q;
    q.push(0);
    d[0] = 0;
    while (sz(q)) {
        int now = q.front();
        q.pop();
        for (int nxt : g[now]) {
            if (d[nxt] != -1) continue;
            d[nxt] = d[now] + 1;
            q.push(nxt);
        }
    }
    rep(i, n) 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 <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>
 
#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
 
using namespace std;
 
typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;
 
const int INF=1<<29;
const double EPS=1e-9;
 
const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};

std::vector<vector<int> > G;
std::vector<int> flag;
std::vector<int> in;
int N;
typedef pii P;

int main(int argc, char const *argv[]) {
	
	cin >> N;

	for (int i = 0; i < N; ++i) {
		G.push_back(vector<int>());
		flag.push_back(0);
		in.push_back(0);
		for (int j = 0; j < N; ++j) {
			G[i].push_back(0);
		}
	}

	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;
		}
	}
	queue<P> q;
	q.push(mp(0, 0));
	while(!q.empty()) {
		P u = q.front(); q.pop();
		int dist = u.second;
		in[u.first] = dist;
		for (int i = 0; i < N; ++i) {
			if (flag[i] == 0 && G[u.first][i] == 1) {
				q.push(mp(i, dist + 1));
				flag[i] = 1;
			}
		}
	}

	for (int i = 0; i < N; ++i) {
		cout << i + 1 << " " << in[i] << endl;
	}

	return 0;
}

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;
}