Go: package main

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

func main() {
	scn := bufio.NewScanner(os.Stdin)
	scn.Split(bufio.ScanWords)
	nextInt := func() int { scn.Scan(); r, _ := strconv.Atoi(scn.Text()); return r }
	w := bufio.NewWriter(os.Stdout)

	n := nextInt()
	vecs := make([][]int, n)
	for i := 0; i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			vecs[u-1] = append(vecs[u-1], nextInt()-1)
		}
	}

	ds := make([]int, 0, n)
	for i := 0; i < n; i++ {
		ds = append(ds, -1)
	}

	q := make([]int, 0, n)
	q = append(q, 0)
	ds[0] = 0

	for len(q) > 0 {
		i := pop(&q)
		for _, v := range vecs[i] {
			if ds[v] == -1 {
				ds[v] = ds[i]+1
				q = append(q, v)
			}
		}
	}

	for i, d := range ds {
		fmt.Fprintln(w, i+1, d)
	}

	w.Flush()
}

func pop(q *[]int) int {
	v := (*q)[0]
	*q = (*q)[1:]
	return v
}

C++: #include<queue>
#include<queue>
#include<string>
#include<iostream>
#include<algorithm>
using namespace std;

int n, dd[101], f[101], tmap[101][101];
int color[101], t = 0;
queue<int> Q;


void a(){
	while (!Q.empty()){
		int d = Q.front();
		Q.pop();
		for (int i = 1; i <= n; i++){
			if (color[i] == 0 && tmap[d][i] == 1){
				Q.push(i);
				color[i] = 1;
				dd[i] = dd[d] + 1;
			}
		}
	}
}


int main(){
	cin >> n;
	for (int i = 0; i < 100; i++){
		f[i] = color[i] = 0;
		dd[i] = -1;
		for (int j = 0; j < 100; j++){
			tmap[i][j] = 0;
		}
	}

	int u, k, v;

	for (int i = 0; i < n; i++){
		cin >> u >> k;
		for (int j = 0; j < k; j++){
			cin >> v;
			tmap[u][v] = 1;
		}
	}
	color[1] = 1;
	Q.push(1);
	dd[1] = t;
	a();
	for (int i = 1; i <= n; i++){
		cout << i << " " << dd[i] << endl;
	}
	return 0;
}

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

#define REP(i,n) for(int i=0;i<(n);i++)
#define REAP(i,a,n) for(int i=(a);i<(n);i++)
#define YES cout<<"Yes"<<endl
#define NO cout<<"No"<<endl
#define fr first
#define sc second
#define pb push_back
#define All(v) v.begin(),v.end()
typedef long long ll;

int table[101][101];

void init(){
    REP(i,101){
        REP(j,101){
            table[i][j]=1e9;
            if(i==j)table[i][j]=0;
        }
    }
}

int main(){
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    init();
    int u,k,v;
    REP(i,n){
        cin >> u >> k;
        REP(j,k){
            cin >> v;
            table[u-1][v-1]=1;
        }
    }

    REP(i,n){
        REP(j,n){
            REP(k,n){
                table[i][j]=min(table[i][j],table[i][k]+table[k][j]);
            }
        }
    }
    REP(i,n){
        cout << i+1 << " " << ((table[0][i]<n)?table[0][i]:-1);
        cout << endl;
    }
}

C++: #include <iostream>
#include <queue>
#define INFTY -10000000
using namespace std;



int a[124][124] = {{}};
int d[124] = {};
int n;
void bfs(int k){
  queue <int> q;
  q.push(k);
  int u;


  while(!q.empty()){
    u = q.front(); q.pop();
    for(int v = 0;v < n;v++){
      if(a[u][v] == 0) continue;
      if(d[v] == INFTY) {
        d[v] = d[u] + 1;
        //cout << v << " " << d[v] << endl;
      }
      q.push(v);
    }

  }
}

int main(){

  int u,k,x;
  cin >> n;

d[0] = 0;
for(int i = 1; i < n;i++) d[i] = INFTY;

  for(int i = 0;i < n;i++){
    cin >> u >> k;
    for(int j = 0;j < k;j++){
      cin >> x;
      a[u - 1][x - 1] = 1;
    }
  }

  bfs(0);

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

C++: #include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <ctime>
#include <string>
#include <queue>

using namespace std;

const int MAX_N = 100;
int n;
int suji[MAX_N];
int	num[MAX_N];
int adj[MAX_N][MAX_N];
int ans[MAX_N][MAX_N];
int D[MAX_N];

void bfs(int src){
	queue<int> Q;
	Q.push(src);
	D[src] = 0;

	while(!Q.empty()){
		int cur = Q.front();
		Q.pop();

		for(int i = 0; i < n; i++){
			if(ans[cur][i] == 1 && D[i] == 0){
				D[i] = D[cur] + 1;
				Q.push(i);
			}
		}
	}
}


int main(void){

	cin >> n;
	for(int i = 0; i < n; i++){
		
		cin >> suji[i] >> num[i];

		
		for(int j = 0; j < num[i]; j++){
			cin >> adj[i][j];
			adj[i][j] -= 1;
		}
	}

	for(int i = 0; i < n; i++){
		for(int j = 0; j < n; j++){
			ans[i][j] = 0;
		}
	}

	for(int i = 0; i < n; i++){
		for(int j = 0; j < num[i]; j++){
			ans[i][adj[i][j]] = 1;
		}
	}

	bfs(0);

	for(int i = 0; i < n; i++){
		cout << i + 1 << " " << D[i] << endl;
	}
	
    return 0;
}

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

using namespace std;

void bfs(int v,vector<vector<int>>& vertex, int d[]);

int depth = 0;

int main(){
    int n;
    cin >> n;
    int num;
    int tmp2;
    int d[n] = {};
    vector<vector<int>> vertex;
    vector<int> tmp;
    for(int i=0;i<n;i++){
        cin >> num;
        cin >> num;
        for(int j=0;j<num;j++){
            cin >> tmp2;
            tmp.push_back(tmp2-1);
        }
        vertex.push_back(tmp);
        tmp.clear();
    }
    bfs(0, vertex, d);
    for(int i=0;i<n;i++){
        cout << i+1 << " " <<  d[i] << endl;
    }
    return 0;
}

void bfs(int v, vector<vector<int>>& vertex, int d[]){
    queue<int> Q;
    d[v] = depth++;
    Q.push(v);
    while(!Q.empty()){
        v = Q.front();
        Q.pop();
        for(int i : vertex[v]){
            if(d[i]==0){
                d[i] = depth;
                Q.push(i);
            }else{
                depth++;
            }
        }
    }
}