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 <bits/stdc++.h>
using namespace std;

typedef vector<int> Adj_list;
typedef vector<Adj_list> Adj_lists;

void bfs(const int& i, const Adj_lists& adj_lists, vector<int>& distances){

  distances.at(i-1) = 0;

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

  while(!q.empty()){
    // visit top of queue
    const int& visit = q.front();
    const Adj_list& adj_list = adj_lists.at(visit-1);

    // push adjecent node which is not visited yet
    for(const int& adj : adj_list){
      if(distances.at(adj-1) == -1){
        distances.at(adj-1) = distances.at(visit-1) + 1;
        q.push(adj);
      }
    }

    q.pop();
  }
}

int main(){

  int n;
  scanf("%d", &n);

  Adj_lists adj_lists(n);
  for(int i=0; i<n; i++){
    int u, k;
    scanf("%d %d", &u, &k);
    Adj_list adj_list(k);
    for(int j=0; j<k; j++){
      int v;
      scanf("%d", &v);
      adj_list[j] = v;
    }
    sort(adj_list.begin(), adj_list.end());
    adj_lists[u-1] = adj_list;
  }

  vector<int> distances(n);
  for(int& distance : distances) distance = -1;

  bfs(1, adj_lists, distances);

  for(int i = 0; i < distances.size(); i++){
    printf("%d %d\n", i+1, distances.at(i));
  }

  return 0;
}

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

using namespace std;

#define GRAPH_SIZE 101
#define START_INDEX 1

enum color_t {
  WHITE,
  GRAY,
  BLACK,
};

struct data_t {
  uint32_t index;
  vector<uint32_t> connection;
  uint32_t distance;
};

static vector<uint32_t> graph[GRAPH_SIZE];
static color_t state[GRAPH_SIZE];

void breadth_first_search(void (*callback)(uint32_t, uint32_t))
{
  for (uint32_t i = START_INDEX; i < GRAPH_SIZE; i++) {
    state[i] = WHITE;
  }

  queue<data_t> queue;

  data_t data;
  data.index = START_INDEX;
  data.connection = graph[START_INDEX];
  data.distance = 0;

  queue.push(data);
  state[START_INDEX] = GRAY;

  while (!queue.empty()) {
    data_t top = queue.front();
    queue.pop();

    state[top.index] = BLACK;
    callback(top.index, top.distance);

    for (uint32_t i = 0; i < top.connection.size(); i++) {
      if (state[top.connection[i]] == WHITE) {
        data_t data;
        data.index = top.connection[i];
        data.connection = graph[top.connection[i]];
        data.distance = top.distance + 1;
        queue.push(data);
        state[data.index] = GRAY;
      }
    }
  }
}

#include <iostream>

int32_t distances[GRAPH_SIZE];

static void callback(uint32_t index, uint32_t distance)
{
  distances[index] = distance;
}

int32_t main()
{
  uint32_t num;
  cin >> num;

  for (uint32_t i = START_INDEX; i < START_INDEX + num; i++) {
    distances[i] = -1;
  }

  for (uint32_t i = 0; i < num; i++) {
    uint32_t index, len;
    cin >> index >> len;
    for (uint32_t j = 0; j < len; j++) {
      uint32_t val;
      cin >> val;
      graph[index].push_back(val);
    }
  }

  breadth_first_search(callback);

  for (uint32_t i = START_INDEX; i < START_INDEX + num; i++) {
    cout << i << " " << distances[i] << endl;
  }

  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> P;
constexpr int di[] = {0, 1, 0, -1}, dj[] = {1, 0, -1, 0};
#define rep(i, n) for (int i = 0; i < n; i++)
#define repr(i, n) for (int i = n; i >= 0; i--)
#define sort(v) sort((v).begin(), (v).end())
#define sortr(v) sort((v).rbegin(), (v).rend())
#define all(v) (v).begin(), (v).end()
#define max 100005
#define nil -1

constexpr int inf = 1000000;
vector<vector<int>> g;
vector<int> d;

void bfs(int s){
    d.resize(max);
   fill(d.begin(),d.end(),inf);
   d[s]=0;
   queue<int> q;
   q.push(s);
   while(!q.empty()){
       int now=q.front();
       q.pop();
       for(auto &e:g[now]){
           if(d[e]==inf){
               d[e]=d[now]+1;
               q.push(e);
           }
       }
   }
}

int main() {
  int  n,u,k,v;
  cin>>n;
    g.resize(n);
    d.resize(n);
  rep(i,n){
      cin>>u>>k;
      u--;
      for(int j=0;j<k;j++){
          cin>>v;
          v--;
          g[u].push_back(v);
        }
    }
    bfs(0);
    rep(i,n){
        if(d[i]<inf){
            cout<<i+1<<" "<<d[i]<<endl;
        }else{
            cout<<i+1<<" "<<-1<<endl;
        }
    }
  return 0;
}

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

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;
		u--;
		for (int j = 0; j < k; j++) {
			int v;
			cin >> v;
			v--;
			G[u].push_back(v);
		}
	}

	vector<int> dist(n, -1);
	queue<int> q;
	q.push(0);
	dist[0] = 0;

	while (!q.empty()) {
		int v = q.front();
		q.pop();

		for (int nv : G[v]) {
			if (dist[nv] != -1) continue;
			dist[nv] = dist[v] + 1;
			q.push(nv);
		}
	}

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