Go: package main

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

type AdjacentList struct {
	matrix [][]int
}

func NewEmptyAdjacentList(dim int) *AdjacentList {
	matrix := make([][]int, dim)
	for i := 0; i < dim; i++ {
		matrix[i] = make([]int, dim)
	}
	return &AdjacentList{matrix: matrix}
}

func (al *AdjacentList) set(node int, adjacent int) {
	al.matrix[node-1][adjacent-1] = 1
}

func (al *AdjacentList) findAdjacentsFor(node int) []int {
	adjacents := []int{}
	for i, v := range al.matrix[node-1] {
		if v == 1 {
			adjacents = append(adjacents, i+1)
		}
	}
	return adjacents
}

type DistanceList struct {
	list []int
}

func NewDistanceList(dim int) *DistanceList {
	list := make([]int, dim)
	for i := 0; i < dim; i++ {
		list[i] = -1
	}
	return &DistanceList{list: list}
}

func (dl *DistanceList) set(node int, distance int) {
	dl.list[node-1] = distance
}

func (dl *DistanceList) get(node int) int {
	return dl.list[node-1]
}

func (dl *DistanceList) isVisited(node int) bool {
	return dl.list[node-1] >= 0
}

type Position struct {
	node     int
	distance int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	dim, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	al := NewEmptyAdjacentList(dim)

	for i := 1; i <= dim; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}

		adjacentNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		for j := 0; j < adjacentNum; j++ {
			adjacent, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			al.set(node, adjacent)
		}
	}

	dl := NewDistanceList(dim)

	bfs(al, dl)

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

func bfs(al *AdjacentList, dl *DistanceList) {
	stack := []Position{Position{node: 1, distance: 0}}
	for len(stack) > 0 {
		currentPosition := stack[0]
		stack = stack[1:]
		if !dl.isVisited(currentPosition.node) {
			dl.set(currentPosition.node, currentPosition.distance)
		}
		for _, v := range al.findAdjacentsFor(currentPosition.node) {
			if !dl.isVisited(v) {
				stack = append(stack, Position{node: v, distance: currentPosition.distance + 1})
			}
		}
	}
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include<iostream>
#include<queue>
#define N 100
#define NIL -1

int M[N][N];
int d[N];
int n;

// 初期化処理後、sを開始地点として幅優先探索を行い、探索結果を出力する
// d[N]にはsからの距離を記録し(sは0)、sからたどり着けない頂点はNIL(空)を記録する
void bfs(int s)
{
	for (int i = 0; i < n; i++)d[i] = NIL;

	std::queue<int> Q;
	Q.push(s);
	d[s] = 0;

	while (!Q.empty())
	{
		int u = Q.front();
		Q.pop();
		for (int v = 0; v < n; v++)
		{
			if (M[u][v] == 0)continue;
			if (d[v] != NIL) continue;
			Q.push(v);
			d[v] = d[u] + 1;
		}
	}

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

int main()
{
	std::cin >> n;
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < n; j++)
		{
			M[i][j] = 0;
		}
	}

	int u, v, k;
	for (int i = 0; i < n; i++)
	{
		std::cin >> u >> k;
		u--;
		for (int j = 0; j < k; j++)
		{
			std::cin >> v;
			v--;
			M[u][v] = 1;
		}
	}
	bfs(0);
}

C++: #include<cstdio>
#include<algorithm>
#include<queue>
#include<vector>
#include<map>
using namespace std;
typedef pair< int, int > Pi;
const int INF = 1 << 30;
struct edge: vector< Pi > {
  void add_edge(int to, int cost){
    push_back(Pi(to,cost));
  }
} info[100000];
int hoge[100000];
 
void bfs(const int& st, const int& V){
  fill_n( hoge, V, INF);
  queue< int > que;
  que.push(st);
  hoge[st] = 0;
  while(!que.empty()){
    int p = que.front();
    que.pop();
    for(int i = 0 ; i < info[p].size() ; i++){
      int cost = info[p][i].second;
      int to = info[p][i].first;
      if( cost + hoge[p] < hoge[to]){
        que.push(to);
        hoge[to] = cost + hoge[p];
      }
    }
  }
}
 
int main(){
  int N;
  scanf("%d", &N);
  for(int i = 0; i < N; i++){
    int u, k;
    scanf("%d %d", &u, &k);
    u--;
    while(k--){
      int v;
      scanf("%d", &v);
      info[u].add_edge( v - 1, 1);
    }
  }
  bfs(0, N);
  for(int i = 0 ; i < N ; i++ ){
    printf("%d %d\n", i + 1, hoge[i]==INF?-1:hoge[i]);
  }
}

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(-1);
		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 <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)
      {
        // 繋がってない
        continue;
      }
      if (d[v] != INFTY)
      {
        // 訪問済
        continue;
      }
      d[v] = d[u] + 1; // 一つ先
      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 <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;

#define pb push_back
#define rep(i, n) for(int i = 0; i < (n); i++)
#define FOR(i, a, n) for(int i = a; i < (n); i++)
#define mod (ll)(1e9+7)
#define int ll

__attribute__((constructor))
void initial() {
  cin.tie(0);
  ios::sync_with_stdio(false);
}

ll graph[101][101] = {{}}, d[101] = {}, n;

void bfs(int v) {
  queue<int> q;
  q.push(v);
  ll u;
  for(int i = 1; i <= n; i++) d[i] = -1;
  d[v] = 0;
  while(!q.empty()) {
    u = q.front(); q.pop();
    for(int i = 1; i <= n; i++) {
      if(graph[u][i] == 0) continue;
      if(d[i] != -1) continue;
      d[i] = d[u] + 1;
      q.push(i);
    }
  }
}

signed main() {
	ll u, v, k;
  cin >> n;
  rep(i, n) {
    cin >> u >> k;
    rep(j, k) {
      cin >> v;
      graph[u][v] = 1;
    }
  }

  bfs(1);

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

	return 0;
}