Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	visitedAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		visitedAt: -1,
		adjs: adjs,
	}
}

func (v *vertex) isVisited() bool {
	return v.visitedAt >= 0
}

func bfs(id vertexId, vqueue []vertexId, vertices []vertex) {
	vertex := &vertices[id-1]
	for _, vid := range vertex.adjs {
		if !vertices[vid-1].isVisited() {
			(&vertices[vid-1]).visitedAt = vertex.visitedAt+1
			vqueue = append(vqueue, vid)
		}
	}
	if len(vqueue) > 0 {
		nextId := vqueue[0]
		nextVqueue := vqueue[1:]
		bfs(nextId, nextVqueue, vertices)
	}
}

func solveBfs(vertices []vertex) {
	vertex := &vertices[0]
	vertex.visitedAt = 0
	vqueue := make([]vertexId, 0)
	bfs(vertex.id, vqueue, vertices)
}

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

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

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	solveBfs(vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d\n", vertices[i].id, vertices[i].visitedAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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

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

static const int MAX_NUM = 101;
static const int NO_VISIT  = 0;
//static const int NOW_VISIT = 1;
static const int END_VISIT = 2;

void BFS(int *matrix, int num)
{
    int i;
    int state[MAX_NUM]    = {0};
    int distance[MAX_NUM] = {0};
    queue<int> Q;
    int target;
    int dist = 0;
    int *tmp;
    bool first;

    Q.push(1);
    state[1] = END_VISIT;
    while (Q.empty() == false) {
        target = Q.front();
        Q.pop();
        tmp = matrix + target * MAX_NUM;
        first = true;
        for (i = 1; i <= num; i++) {
            if ((*(tmp + i) == 1) && (state[i] == NO_VISIT)) {
                if (first == true) {
                    ++dist;
                    first = false;
                }
                distance[i] = dist;
                Q.push(i);
                state[i] = END_VISIT;
            }
        }
    }

    for (i = 1; i <= num; i++) {
        printf("%d %d\n", i, distance[i]);
    }

    return;
}

int main(void)
{
    int i, j;
    int num;
    int elem;
    int nume;
    int tmp;
    int matrix[MAX_NUM][MAX_NUM];

    scanf("%d", &num);
    for (i = 0; i < num; i++) {
        scanf("%d %d", &elem, &nume);
        for (j = 0; j < nume; j++) {
            scanf("%d", &tmp);
            matrix[elem][tmp] = 1;
        }
    }

    BFS(&matrix[0][0], num);

    return 0;
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include "bits/stdc++.h"

using namespace std;

#define REP(x,l,u) for(ll x = l;x<u;x++) // for loop
#define RREP(x,l,u) for(ll x = l;x>=u;x--) // reverse for loop

/**
 *  debugging stuff
 */
string to_string(string s) {return s;}
string to_string(char c) {return string(1,c);}
template <typename A, typename B> string to_string(pair<A,B> p) { return "(" + to_string(p.first) + ", " + to_string(p.second) + ")"; }
template <typename A> string to_string(vector<A> v) { string s = "("; int first = 1; for (A a : v) { if (!first) { s += ", "; } first = 0; s += to_string(a); } s += ")"; return s; }
template <typename A> string to_string(set<A> v) { string s = "("; int first = 1; for (A a : v) { if (!first) { s += ", "; } first = 0; s += to_string(a); } s += ")"; return s; }

/**
 *  more debugging stuff
 */
void debug_out() {cerr << endl;}
template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) { cerr << " " << to_string(H); debug_out(T...); }

#ifndef ONLINE_JUDGE
#define debug(...) do { cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__); } while (false)
#else
#define debug(...) do { } while (false)
#endif

typedef long long ll;
typedef double db;
typedef vector<ll> VLL;
typedef vector<VLL> VVLL; 
typedef pair<ll,ll> PLL;
typedef vector<string> VS;

template <typename A, typename B> void in(A & a, B & b) { in(a); in(b); }
template <typename A, typename B, typename C> void in(A & a, B & b, C & c) { in(a); in(b); in(c); }

const ll inf = (ll)1e18 + 5;

ll V;

VLL bfs(ll source, VVLL & adj_list) {

    VLL distance((V+2), inf);
    queue<ll> Q;

    Q.push(source);
    distance[source] = 0;

    while (Q.size()) {
        // pop front of queue
        ll at = Q.front();
        Q.pop();

        for (ll to : adj_list[at]) {

            if (distance[to] == inf) {
                Q.push(to);
                distance[to] = distance[at] + 1;
            }

        }
    }

    return distance;
}

namespace SOLVE {	
	void main() {
    

        cin >> V;
        ll vertex;

        VVLL adj_list(V+1);

        // create adjacency list
        REP (i,1,V+1) {
            cin >> vertex;

            ll adj_vertices;

            cin >> adj_vertices;

            REP (j,0,adj_vertices) {

                ll add_vertex;
                cin >> add_vertex;
                adj_list[vertex].push_back(add_vertex);
            }
        }

        VLL distance = bfs(1, adj_list);

        REP(i,1,V+1) {
            if (distance[i] == inf) {
                distance[i] = -1;
            }
            cout << i << " " << distance[i] << endl;
        }
	}
}

signed main() {
	ll t;
	t = 1;
    // cin >> t;
	REP(i,0,t) {
		SOLVE::main();
	}

	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);

  return 0;
}