Go: package main

import (
	"container/list"
	"fmt"
	"bufio"
	"os"
	"strconv"
)

const (
	N   = 100
	INF = 1 << 21
)

var (
	n        int
	adj      [N][N]int
	distance [N]int
)

func BFS(start int) {
	q := list.New()
	q.PushBack(start)
	for i := 0; i < n; i++ {
		distance[i] = INF
	}
	distance[start] = 0
	u := 0
	for q.Len() != 0 {
		u = q.Remove(q.Front()).(int)
		for v := 0; v < n; v++ {
			if adj[u][v] == 0 {
				continue
			}
			if distance[v] != INF {
				continue
			}
			distance[v] = distance[u] + 1
			q.PushBack(v)
		}
	}
	for i := 0; i < n; i++ {
		var d int
		if distance[i] == INF {
			d = -1
		} else {
			d = distance[i]
		}
		fmt.Printf("%d %d\n", i+1, d)
	}
}

func main() {
	var u, k, v int
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	scanner.Scan()
	n, _ = strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			adj[i][j] = 0
		}
	}
	for i := 0; i < n; i++ {
		scanner.Scan()
		u, _ = strconv.Atoi(scanner.Text())
		u -= 1
		scanner.Scan()
		k, _ = strconv.Atoi(scanner.Text())
		for j := 0; j < k; j++ {
			scanner.Scan()
			v, _ = strconv.Atoi(scanner.Text())
			v -= 1
			adj[u][v] = 1
		}
	}
	BFS(0)
}

C++: #include<bits/stdc++.h>
#define ll long long
#define rep(i, n) for(int i=0; i<n; i++)
#define REP(i, n) for(int i=0; i<=n; i++)
#define repr(i, n) for(int i=n; i>0; i--)
#define REPR(i, n) for(int i=n; i>=0; i--)
const ll INF = 1LL<<60;
const int INT_INF = 1e9;
const ll MOD = 1e9+7;
template<class T> void puts(T x) { std::cout << x << std::endl; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
using namespace std;

enum State {
    unseen, // 未訪問
    seen,   // 発見済み
    end     // 探索終了
};

vector<vector<int>> adj; // 隣接行列
int t = 0;  // 大域時刻
int d[110]; // 各頂点の頂点1からの最短距離
State s[110];


int main() {
    int n; cin >> n;
    adj.resize(n);
    rep(i, n) {
        int u, k; cin >> u >> k;
        --u;
        rep(j, k) {
            int v; cin >> v;
            --v;
            adj[i].emplace_back(v);
        }
    }

    // 初期化
    rep(i, n) {
        d[i] = INT_INF;
        s[i] = State::unseen;
    }
    d[0] = 0;
    queue<int> q;
    q.push(0);

    // BFS
    while (!q.empty()) {
        int u = q.front();
        q.pop();
        for (auto &v: adj[u]) {
            if (d[v] == INT_INF) {
                q.push(v);
                d[v] = d[u] + 1;
            }
        }
    }

    // 出力
    rep(i, n) {
        int dist = (d[i] != INT_INF) ? d[i] : -1;
        cout << i+1 << ' ' << dist << endl;
    }
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>
 
#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
 
using namespace std;
 
typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;
 
const int INF=1<<29;
const double EPS=1e-9;
 
const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};

std::vector<vector<int> > G;
std::vector<int> flag;
std::vector<int> in;
int N;


int main(int argc, char const *argv[]) {
	
	cin >> N;

	for (int i = 0; i < N; ++i) {
		G.push_back(vector<int>());
		flag.push_back(0);
		in.push_back(0);
		for (int j = 0; j < N; ++j) {
			G[i].push_back(0);
		}
	}

	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][v] = 1;
		}
	}
	using P = pair<int,int>;
	queue<P> q;
	q.push(mp(0, 0));
	while(!q.empty()) {
		P u = q.front(); q.pop();
		int dist = u.second;
		in[u.first] = dist;
		for (int i = 0; i < N; ++i) {
			if (flag[i] == 0 && G[u.first][i] == 1) {
				q.push(mp(i, dist + 1));
				flag[i] = 1;
			}
		}
	}

	for (int i = 0; i < N; ++i) {
		cout << i + 1 << " " << in[i] << endl;
	}

	return 0;
}

C++: // #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(v) v.begin(), v.end()
#define Graph vector< vector<int> >
typedef long long ll;
typedef pair<int, int> P;
const int INF = 1000000007;

int main(){
    int N;
    cin >> N;
    Graph G(N);
    rep(i, N){
        int u, k;
        cin >> u >> k;
        u--;
        rep(j, k){
            int v;
            cin >> v;
            v--;
            G[u].push_back(v);
        }
    }

    vector<int> dist(N, -1);
    dist[0] = 0;

    queue<int> que;
    que.push(0);

    while(!que.empty()){
        int v = que.front();
        que.pop();
        for(int i = 0; i < G[v].size(); i++){
            int v2 = G[v][i];
            if(dist[v2] != -1) continue;
            dist[v2] = dist[v] + 1;
            que.push(v2);
        }
    }

    rep(i, N){
        cout << i + 1 << ' ' << dist[i] << endl;
    }
}

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

using edges = vector<int>;
using Graph = vector<edges>;

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);
        }
    }
    queue<int> que;
    que.emplace(0);
    vector<int> dis(n, -1);
    dis[0] = 0;
    while (!que.empty()) {
        int v = que.front(); que.pop();
        for (int nv : g[v]) if (dis[nv] < 0) {
            dis[nv] = dis[v] + 1;
            que.emplace(nv);
        }
    }
    for (int i = 0; i < n; ++i) {
        cout << i + 1 << " " << dis[i] << endl;
    }
}

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

using namespace std;
static const int INF = 1e9;
static const int SIZE = 101;
typedef pair<int, int> P;

int d[SIZE];
vector<int> G[SIZE];

void solve()
{
	int n;
	cin >> n;
	for (int i = 0; i < n; ++i)
	{
		int u, k;
		cin >> u >> k;
		for (int j = 0; j < k; ++j)
		{
			int v;
			cin >> v;
			G[u].push_back(v);
		}
	}
	for (int i = 0; i < SIZE; ++i)
	{
		d[i] = INF;
	}
	d[1] = 0;
	queue<P> que;
	que.push(P(0, 1));
	while (!que.empty())
	{
		P p = que.front();
		que.pop();
		int v = p.second;
		for (int i = 0; i < G[v].size(); ++i)
		{
			int to = G[v][i];
			if (d[to] > p.first + 1)
			{
				d[to] = p.first + 1;
				que.push(P(d[to], to));
			}
		}
	}
	for (int i = 1; i <= n; ++i)
	{
		cout << i << " " << d[i] << endl;
	}
}

int main()
{
	solve();
	return(0);
}

C++: #include <iostream>
#include <array>
#include <algorithm>
#include <stack>
#include <queue>

const int nmax = 105;
const int NIL = -1;
int n;
// state of vertex
// 0: not visited
// 1: visited
// 2: complete search from the vertex
std::array<int, nmax> color, d;

std::array<std::array<int, nmax>, nmax> adj;

void bfs(int v)
{
  std::queue<int> q;
  q.push(v);
  d[v] = 0;

  while (!q.empty())
    {
      v = q.front();
      for (int i=0; i<n; ++i)
        {
          if (adj[v][i] == 1 && d[i] == NIL)
            {
              q.push(i);
              d[i] = d[v] + 1;
            }
        }
      q.pop();

    }
}
int main ()
{
  std::cin >> n;

  color.fill(0);
  std::for_each(adj.begin(), adj.end(), [](auto x){x.fill(0);});
  for (int i=0; i<n; ++i)
    {
      int u, k;
      std::cin >> u >> k;
      for (int j=0; j<k; ++j)
        {
          int v;
          std::cin >> v;
          adj[u-1][v-1] = 1;
        }
    }

  d.fill(NIL);
  bfs(0);

  for (int i=0; i<n; ++i)
    {
      std::cout << i+1 << ' ' << d[i] << std::endl;
    }
}