Go: package main

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

type Pair struct {
	v int
	d int
}

type Queue []Pair

func (q *Queue) push(v Pair) {
	*q = append(*q, v)
}

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

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

	nVerts := scanInt(sc)
	graph := make([][]int, nVerts+1)

	for i := 0; i < nVerts; i++ {
		u := scanInt(sc)
		nDegrees := scanInt(sc)

		graph[u] = make([]int, nDegrees)
		for d := 0; d < nDegrees; d++ {
			graph[u][d] = scanInt(sc)
		}
	}

	paths := make([]int, nVerts+1)

	queue := Queue(make([]Pair, 0))
	queue.push(Pair{1, 1})
	paths[1] = 1

	for len(queue) > 0 {
		p := queue.pop()
		d := p.d + 1
		for _, v := range graph[p.v] {
			if paths[v] == 0 {
				paths[v] = d
				queue.push(Pair{v, d})
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 1; i <= nVerts; i++ {
		fmt.Fprintf(w, "%d %d\n", i, paths[i]-1)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cassert>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define rep(i,n) FOR(i,0,n)
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define vint vector<int>
#define vdouble vector<double>
#define vstring vector<string>
using namespace std;

#include<map>
#include<set>
#include<queue>

typedef long long ll;
typedef unsigned long long ull;

const int MAX_N = 1000000;
static const int INFTY = (1 << 21);

class Edge{
public:
    int from, to, cost;
    Edge(int from = 0, int to = 0, int cost = 0) :
            from(from), to(to), cost(cost){}

    bool operator < (const Edge &e) const{
        return cost < e.cost;
    }
    bool operator >(const Edge &e) const{
        return cost > e.cost;
    }

};

class Node{
public:
    vector<Edge> edges;
    int dist;

    Node(){
        dist = INFTY;
    }
};

class Graph{
public:
    vector<Node> nodes;
    Graph(int n) {
        rep(i, n) { Node n;  nodes.push_back(n); }
    }
    Node& operator[](int i){
        return nodes[i];
    }
};

class Data{

public:
    int dist;
    Edge *edge;
    Data(int dist, Edge *edge) {
        this->dist = dist;
        this->edge = edge;
    }

    bool operator < (const Data &d) const{
        return dist < d.dist;
    }
    bool operator >(const Data &d) const{
        return dist > d.dist;
    }
};

Graph G(0);
int V;

int main() {

    cin >> V;
    G = Graph(V);

    rep(i, V){
        int from; cin >> from; from--;
        int e_count; cin >> e_count;

        vint vec;
        rep(j, e_count){
            int to; cin >> to; to--;
            vec.push_back(to);
        }
        sort(vec.begin(), vec.end());
        rep(j, e_count){
            G[from].edges.push_back(Edge(from, vec[j], 1));
        }
    }

    // bfs
    queue<Data> q;
    Edge e(-1, 0, 0);
    q.push(Data(0, &e));
    while(!q.empty()){
        Data d = q.front(); q.pop();
        Edge &e = *(d.edge);
        Node &n = G[e.to];

        if(n.dist != INFTY) continue;
        n.dist = d.dist;

        for(auto &ee: n.edges){
            q.push(Data(n.dist+1, &ee));
        }
    }

    rep(i, V) {
        if (G[i].dist == INFTY) G[i].dist = -1;
    }

    rep(i, V){
        fprintf(stdout, "%d %d\n", i+1, G[i].dist);
    }
}

C++: #include <cstdio>
#include <iostream>
#include <vector>
#include <cstring>
#include <queue>
#include <algorithm>
#include <utility>
#define rep(i,n) for(int i=0; i<(n); ++i)
#define reps(i, s, n) for(int i=(s); i<=(n); ++i)
#define outl(x) cout<< (x) << '\n'
#define fi first
#define se second
#define mkp make_pair

#define INF 0x3f3f3f3f
using namespace std;

int N;
vector <int> G[102];
int far[102];

void slv()
{
   queue <int> que;
   que.push(1);
   memset( far, INF, sizeof(far) );
   far[1] = 0;

   while(!que.empty()){
      const int u = que.front();
      que.pop();
      rep(i, G[u].size()){
         const int next = G[u][i];
         if(far[u] + 1 < far[next]){
            far[next] = far[u] + 1;
            que.push( next );
         }
      }
   }

   reps(i, 1, N){
      cout << i <<  ' ' << ( far[i] == INF ? -1 : far[i] ) << '\n';
   }
   return;
}

signed main()
{
   cin.tie(0), ios::sync_with_stdio(false);
   cin >> N;

   reps(i, 1, N){
      int u, k, a;
      cin >> u >> k;
      while(k--){
         cin >> a;
         G[u].push_back(a);
      }
   }

   slv();
   return (0);
}

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

// 総数を1000000007で割った余り
const long long mod = 1e9 + 7;

using ll  = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define ull unsigned long long
#define ld long double
#define vi vector<int>
#define vll vector<ll>
#define vc vector<char>
#define vs vector<string>
#define vpii vector<pii>
#define vpll vector<pll>

#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; i++)
#define rep1(i, n) for (int i = 1, i##_len = (n); i <= i##_len; i++)
#define repr(i, n) for (int i = ((int)(n)-1); i >= 0; i--)
#define rep1r(i, n) for (int i = ((int)(n)); i >= 1; i--)

#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

#define SORT(v, n) sort(v, v + n);
// #define SORT(v, n) stable_sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define RSORT(x) sort(rall(x));
#define pb push_back
#define mp make_pair

#define INF (1e9)
#define PI (acos(-1))
#define EPS (1e-7)

ull gcd(ull a, ull b) { return b ? gcd(b, a % b) : a; }
ull lcm(ull a, ull b) { return a / gcd(a, b) * b; }

const int N     = 100;
const int INFTY = (1 << 21);

int n, M[N][N];
int d[N];  // 距離で訪問状態(color)を管理する。

void bfs(int s) {
    queue<int> q;  //標準ライブラリのqueueを使用。
    q.push(s);
    rep(i, n) d[i] = INFTY;
    d[s]           = 0;
    int u;
    while (!q.empty()) {
        u = q.front();
        q.pop();
        rep(v, n) {
            if (M[u][v] == 0) continue;
            if (d[v] != INFTY) continue;
            d[v] = d[u] + 1;
            q.push(v);
        }
    }
    rep(i, n) {
        cout << i + 1 << " " << ((d[i] == INFTY) ? (-1) : d[i]) << endl;
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    // cout << fixed << setprecision(5);

    int u, k, v;
    cin >> n;
    rep(i, n) { rep(j, n) M[i][j] = 0; }
    rep(i, n) {
        cin >> u >> k;
        u--;
        rep(j, k) {
            cin >> v;
            v--;
            M[u][v] = 1;
        }
    }

    bfs(0);

    return 0;
}

C++: #include<bits/stdc++.h>
#define INF 10000000
using namespace std;

int z[100],n,w[100];
int a[100][100];

void bfs(){
  int m;
  z[0]=0;
  queue<int> q;
  q.push(0);
  while(!q.empty()){
    m=q.front();
    q.pop();
    if(w[m]==1) continue;
    w[m]=1;
    for(int i=0;i<n;i++){
      if(a[m][i]==1){
	q.push(i);
	z[i]=min(z[i],z[m]+1);
      }
    }
  }
}


int main(){
  int p,x;
  for(int i=0;i<100;i++){
    z[i]=w[i]=INF;
    for(int j=0;j<100;j++) a[i][j]=0;
  }
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>p>>p;
    for(int j=0;j<p;j++){
      cin>>x;
      a[i][x-1]=1;
    }
  }
  bfs();
  for(int i=0;i<n;i++){
    if(z[i]!=INF) cout<<i+1<<" "<<z[i]<<endl;
    else cout<<i+1<<" "<<-1<<endl;
  }
  return 0;
}

C++: #include<iostream>
#include<vector>
#include<queue>
#include<algorithm>
using namespace std;
int main()
{
  queue<int> Q;
  int n,u,k,vv,cur,dst;
  cin >> n;
  vector<int> D(n,-1);
  vector< vector<int> > v(n);
  for(int i = 0;i < n;++i){
    cin >> u >> k;
    for(int j = 0;j < k;++j){
      cin >> vv;
      v[u - 1].push_back(vv);
    }
    sort(v[u - 1].begin(),v[u - 1].end());
  }
  D[0] = 0;
  Q.push(1);
  while(!Q.empty()){
    cur = Q.front();
    Q.pop();
    for(int i = 0;i < v[cur - 1].size();++i){
      dst = v[cur - 1][i];
      if(D[dst - 1] == -1) D[dst - 1] = D[cur - 1] + 1;
      Q.push(dst);
    }
  }
  for(int i = 0;i < n;++i)
    cout << i + 1 << " " << D[i] << endl;
}