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 <algorithm>
#include <vector>
#include <string>
#include <complex>
#include <stack>
#include <queue>
#include <list>
#include <utility>
#include <set>
using namespace std;

int main(){
    int n;
    cin >> n;
    int g[110][110];
    int i, j;
    int u, k, v;
    int dist[110];
    bool visited[110];
    
    for(i = 0; i < n; i++){
        dist[i] = -1;
        for(j = 0; j < n; j++){
            g[i][j] = 0;
        }
    }
    
    for(i = 0; i < n; i++){
        cin >> u >> k;
        u--;
        for(j = 0; j < k; j++){
            cin >> v;
            v--;
            g[u][v] = 1;
        }
    }
    
    queue<int> q1, q2;
    q1.push(0);
    
    for(i = 0; q1.size(); i++){
        while(!q1.empty()){
            int p = q1.front();
            q1.pop();
            
            if(visited[p]) continue;
            visited[p] = true;
            
            dist[p] = i;
            
            for(j = 0; j < n; j++){
                if(g[p][j]){
                    q2.push(j);
                }
            }
        }
        q1 = q2;
        q2 = queue<int>();
    }
    
    for(i = 0; i < n; i++){
        cout << i+1 << " " << dist[i] << endl;
    }
}

C++: #include <iostream>
#include <iomanip>
#include <string>
#include <stack>
#include <vector>
#include <math.h>
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <map>
#include <set>
#include <queue>
#include <list>
using namespace std;
using pii  = pair<int,int>;
using ll=long long;
using ld=long double;
#define pb push_back
#define mp make_pair
#define rep(i,n) for(int i=0;i<(n);++i)
#define REP(i,a,b) for(int i=(a);i<(b);++i)
#define crep(i) for(char i='a';i<='z';++i)
#define psortsecond(A,N) sort(A,A+N,[](const pii &a, const pii &b){return a.second<b.second;});
#define ALL(x) (x).begin(),(x).end()
#define endl '\n'
int ctoi(const char c){
  if('0' <= c && c <= '9') return (c-'0');
  return -1;
}
long long gcd(long long a, long long b){return (b == 0 ? a : gcd(b, a%b));}
long long lcm(long long a, long long b){return a*b/gcd(a,b);}
constexpr ll MOD=1000000007;
constexpr ld EPS=10e-8;
template<typename T> istream& operator>>(istream& is,vector<T>& v){for(auto&& x:v)is >> x;return is;}
template<typename T,typename U> istream& operator>>(istream& is, pair<T,U>& p){ is >> p.first; is >> p.second; return is;}
template<typename T,typename U> ostream& operator>>(ostream& os, const pair<T,U>& p){ os << p.first << ' ' << p.second; return os;}
template<class T> ostream& operator<<(ostream& os, vector<T>& v){
    for(auto i=begin(v); i != end(v); ++i){
        if(i !=begin(v)) os << ' ';
        os << *i;
    }
    return os;
}

queue<pair<ll,ll>> Q;
vector<vector<ll>> V(107);
ll chek[107];
ll ans[107];

int main(){
    ll N;
    cin >> N;
    ll A,B,C;
    rep(i,N){
        cin >> A >> B;
        rep(j,B){
            cin >> C;
            V[A].pb(C);
        }
    }
    rep(i,N+1){
        ans[i]=-1;
    }
    Q.push(mp(1,0));
    chek[1]=1;
    while(Q.size()>0){
        rep(i,V[Q.front().first].size()){
            if(chek[V[Q.front().first][i]]==0){
                Q.push(mp(V[Q.front().first][i],Q.front().second+1));
                chek[V[Q.front().first][i]]=1;
            }
        }
        ans[Q.front().first]=Q.front().second;
        Q.pop();
    }
    REP(i,1,N+1){
        cout << i << " " << ans[i] << endl;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;
typedef pair<ll, P> P3;
typedef pair<P, P> PP;
constexpr ll MOD = ll(1e9 + 7);
constexpr int IINF = INT_MAX;
constexpr ll LLINF = LLONG_MAX;
constexpr int MAX_N = int(1e5) + 5;
constexpr double EPS = 1e-9;
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()

int main() {
    vector<vector<int> > g;
    int n;
    cin >> n;
    g.resize(n);
    for(int i=0;i<n;i++){
        int v, k;
        cin >> v >> k;
        v--;
        for(int j=0;j<k;j++){
            int u;
            cin >> u;
            u--;
            g[v].push_back(u);
        }
    }
    vector<int> d(n, IINF);
    queue<int> que;
    que.push(0);
    d[0] = 0;
    que.push(0);
    while(!que.empty()){
        int v = que.front();
        que.pop();
        for(auto u : g[v]){
            if(d[u] == IINF){
                d[u] = d[v]+1;
                que.push(u);
            }
        }
    }
    for(int i=0;i<n;i++){
        cout << i+1 << " " << (d[i] < IINF ? d[i] : -1) << endl;
    }
    return 0;
}