Go: package main

import "fmt"

type container struct {
	data []int
}

func (c *container) queue(v int) {
	c.data = append(c.data, v)
}
func (c *container) dequeue(p *int) bool {
	if p == nil || len(c.data) == 0 {
		return false
	}
	*p = c.data[0]
	c.data = c.data[1:len(c.data)]
	return true
}

func main() {
	var n int
	fmt.Scan(&n)
	g := make([][]int, n+1) // 1-indexed
	d := make([]int, n+1)   // 1-indexed
	for i := 1; i <= n; i++ {
		d[i] = -1
		var u, k, v int
		fmt.Scan(&u, &k)
		for j := 0; j < k; j++ {
			fmt.Scan(&v)
			g[u] = append(g[u], v)
		}
	}

	var q container
	d[1] = 0
	q.queue(1)

for len(q.data) > 0  { // 幅優先探索
		var v int
		q.dequeue(&v)
		for i := 0; i < len(g[v]); i++ {
			nv := g[v][i]
		if d[nv] == -1 { // 未訪問
				q.queue(nv)
				d[nv] = d[v] + 1
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d\n", i, d[i])
	}
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <map>
#include <set>
#include <vector>
#include <stack>
#include <queue>
#include <bitset>
#include <algorithm>
#include <numeric>
#include <functional>
using namespace std;

#define Rep(b, e, i) for(int i = b; i <= e; i++)
#define Repr(e, b, i) for(int i = e; i >= b; i--)
#define rep(n, i) Rep(0, n-1, i)
#define repr(n, i) Repr(n-1, 0, i)
#define all(v) (v).begin(), (v).end()
#define pb(v) push_back(v)
#define uniq(v) (v).erase(unique(all(v)),(v).end())
#define bitcnt(x) __builtin_popcount(x)
#define fst first
#define snd second
#define Pqaz(T) priority_queue<T,vector<T>,greater<T>>
#define Pqza(T) priority_queue<T>
#define ENJYU std::ios::sync_with_stdio(false);std::cin.tie(0);

typedef long long ll;
typedef pair<ll, ll> llP;
typedef pair<int, int> intP;

//vector の中身を出力
template <class T>ostream &operator<<(ostream &o,const vector<T>&v)
{o<<"{";for(int i=0;i<(int)v.size();i++)o<<(i>0?", ":"")<<v[i];o<<"}";return o;}

const int MAX = 128;

vector <int> adj[MAX];
int d[MAX];

void solve(void){
	ENJYU;
	int N;
	cin >> N;
	rep(N, i) {
		int u, k;
		cin >> u >> k;
		u--;
		rep(k, i) {
			int v;
			cin >> v;
			v--;
			adj[u].pb(v);
		}
	}
	memset(d, -1, sizeof(d));
	queue <int> q;
	q.push(0);
	d[0] = 0;
	while (!q.empty()) {
		int n = q.front();
		q.pop();
		for (int nv : adj[n]) {
			if (d[nv] >= 0) {
				d[nv] = min(d[nv], d[n] + 1);
				continue;
			}
			d[nv] = d[n] + 1;
			q.push(nv);
		}
	}

	rep(N, i) cout << i+1 << ' ' << d[i] << endl;

}

int main(void){
	solve();
	//cout << "yui(*-v・)yui" << endl;
	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);
}

static const int N = 100;
static const int no = -1;

ll graph[N][N] = {0}, d[N] = {0}, n;

void bfs(int v) {
  queue<int> q;
  q.push(v);
  ll u;
  for(int i = 1; i <= n; i++) d[i] = no;
  d[v] = 0;
  while(!q.empty()) {
    u = q.front(); q.pop();
    for(int i = 1; i <= n; i++) {
      if((graph[u][i] == 0) || (d[i] != no)) 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;
}

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]; // 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);
	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;
}

C++: #include<bits/stdc++.h>

using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)

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

#define MAX 100005
#define INF INT_MAX

vector< vector<int> > adj;
vector<int> d;

int main(int, char**)
{
    int n;
    cin >> n;

    adj.assign(n, vector<int>());
    d.assign(n,-1);
    int u, k, v;
    rep(i,n) {
        cin >> u >> k; u--;
        rep(j,k) {
            cin >> v; v--;
            adj[u].push_back(v);
        }
    }
    queue<int> q;
    q.push(0);
    d[0] = 0;
    while (!q.empty()) {
        int v = q.front(); q.pop();
        for (auto e : adj[v]) {
            if (d[e] != -1) continue;
            d[e] = d[v] + 1;
            q.push(e);
        }
    }
    rep(i,n) {
        cout << i+1 << " " << d[i] << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, a, b) for(int i = a; i < b; i++)
#define Rep(i, a, b) for(int i = a; i <= b; i++)
#define _GLIBCXX_DEBUG
#define Vl vector<ll>
#define Vs vector<string>
#define Vp vector<pair<ll, ll>>
#define ll long long
#define ALL(v) (v).begin(),(v).end()
using namespace std;
const double pi = acos(-1.0);
const ll MOD = 1e9 + 7;
const ll INF = 1LL << 60;

ll d[110]; // 距離
ll w[110][110];
queue<int> qu;
ll White = 0, Gray = 1, Black = 2;
ll color[110];

void solve() {
    Rep(i, 1, 100) d[i] = -1;

    ll n; cin >> n;
    Rep(i, 1, n){
        ll u, k;
        cin >> u >> k;
        Rep(j, 1, k){
            ll v; cin >> v;
            w[i][v] = 1;
        };
    }

    qu.push(1);
    d[1] = 0;
    while(!qu.empty()){
        int u = qu.front(); qu.pop();
        Rep(v, 1, n){
            if(w[u][v] == 1 && color[v] == 0){
                d[v] = d[u] + 1; 
                qu.push(v);
                color[v] = Black;
            }
        }
        color[u] = Black;
    }

    Rep(i, 1, n) cout << i << " " << d[i] << endl;

    return;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    solve();
    return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for(int i = 0; i < n; i++)
using namespace std;
typedef long long ll;

int main(void)
{
    int n;
    cin >> n;
    vector<vector<int> > G(n+1);
    int distv[n + 1];
    rep(i, n+1)
    {
        distv[i] = -1;
    }

    rep(i, n)
    {
        int num, deg;
        cin >> num >> deg;
        rep(j, deg)
        {
            int v;
            cin >> v;
            G[num].push_back(v);
        }
    }

    distv[1] = 0;
    queue<int> q;
    q.push(1);

    while(!q.empty())
    {
        int v = q.front();
        q.pop();
        for(int nv : G[v])
        {
            if(distv[nv] != -1) continue;
            q.push(nv);
            distv[nv] = distv[v] + 1;
        }
    }

    rep(i, n)
    {
        cout << i+1 << " " << distv[i+1] << endl;
    }
    return 0;
}