Go: package main

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

var distance []int

type queue struct {
	q    []int
	head int
	tail int
}

func (q *queue) push(n int) {
	q.q[q.tail] = n
	q.tail++
}

func (q *queue) pop() int {
	q.head++
	return q.q[q.head-1]
}

func (q *queue) isEmpty() bool {
	return q.head == q.tail
}

func makeAdjList() [][]int {
	var n int
	fmt.Scanf("%d", &n)

	adj := make([][]int, n)
	for i := 0; i < n; i++ {
		adj[i] = make([]int, n)
	}

	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		sc.Scan()
		nodeInfo := strings.Split(sc.Text(), " ")
		outDegree, _ := strconv.Atoi(nodeInfo[1])

		if outDegree > 0 {
			for k := 0; k < outDegree; k++ {
				j, _ := strconv.Atoi(nodeInfo[k+2])
				j-- // convert 1 based to 0 based
				adj[i][j] = 1
			}
		}
	}

	return adj
}

func bfs(graph [][]int, s int) {
	distance = make([]int, len(graph))

	infty := -1
	for i := 0; i < len(distance); i++ {
		distance[i] = infty
	}
	distance[s] = 0

	q := &queue{make([]int, 1000), 0, 0}
	q.push(s)

	for !q.isEmpty() {
		u := q.pop()
		for i := 0; i < len(graph); i++ {
			if graph[u][i] == 0 {
				continue // u, i間に辺がない場合
			}
			if distance[i] != infty {
				continue // 訪問済みの場合
			}
			// 訪問するnodeの始点からの距離を設定し、訪問キューに入れる
			distance[i] = distance[u] + 1
			q.push(i)
		}
	}

	// print distance
	for i, d := range distance {
		fmt.Printf("%d %d\n", i+1, d)
	}
}

func main() {
	adj := makeAdjList()
	bfs(adj, 0)
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
using Graph = vector<vector<int>>;

int main(void)
{
	// 頂点数と辺数
	int N;
	cin >> N;

	Graph G(N + 1);
	for (int i = 1; i <= N; i++)
	{
		int u, k, v;
		cin >> u >> k;
		for (int i = 0; i < k; i++)
		{
			cin >> v;
			G[u].push_back(v);
		}
	}

	// BFSのためのデータ構造
	vector<int> dist(N + 1, -1); // 全頂点を未訪問に初期化
	queue<int> que;

	// 初期条件
	dist[1] = 0;
	que.push(1); // 0を橙色頂点に

	// BFS開始
	while (!que.empty())
	{
		int v = que.front();
		que.pop();

		// vから辿れる頂点をすべて探索
		for (int nv : G[v])
		{
			if (dist[nv] != -1) continue; // 発見済みの頂点は探索しない

			//　新たな白色頂点 nv について距離情報を更新しキューに追加
			dist[nv] = dist[v] + 1;
			que.push(nv);
		}
	}

	// 結果出力 (各頂点の頂点 0 からの距離を見る)
	for (int v = 1; v <= N; ++v) cout << v << " " << dist[v] << endl;
}

C++: #include <iostream>
#include<string>
#include<cmath>
#include<algorithm>
#include<cctype>
#include<queue>
#include<stack>
#include<stdio.h>
#include<vector>
#include<set>
#include<map>
#include<array>
#include<iomanip>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
static const int N=100;
static const int inf=(1<<29);
int M[N][N];
int d[N];
int n;

void dfs(int u){
    rep(i,n)d[i]=inf;
    
    queue<int> q;
    q.push(u);
    d[u]=0;
    int l;
    while(!q.empty()){
        l=q.front();
        q.pop();
        for(int v=0;v<n;v++){
            if(M[l][v]==0)continue;
            if(d[v]!=inf)continue;
            d[v]=d[l]+1;
            q.push(v);
        }
    }
    
    rep(i,n){
        cout<<i+1<<" "<<(d[i]==inf?-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;
        }
    }
    dfs(0);
    
}

C++: #include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i < (n + 1); ++i)
using namespace std;
using ll = long long;
const int INF = +100100100;
// typedef pair<int,int> P;

vector<int> D(150, INF);
vector<vector<int>> M(150, vector<int>(150));
int n;

void bfs()
{
    int s = 0;
    queue<int> Q;
    Q.push(s);
    D[0]=0;
    while (!Q.empty())
    {
        int u = Q.front();
        Q.pop();
        rep(v, n)
        {
            // 訪れたことがない
            if (D[v] == INF&&M[u][v]==1)
            {
                D[v] = D[u] + 1;
                Q.push(v);
            }
        }
    }
    rep(i,n)if(D[i]==INF)D[i]=-1;
}

int main()
{
    cin >> n;
    vector<list<int>> L(n);
    rep(i, n)
    {
        int u, e;
        cin >> u >> e;
        rep(j, e)
        {
            int v;
            cin >> v;
            --v;
            L[i].push_back(v);
        }
    }
    
    rep(i, n)
    {
        rep(j, n)
        {
            list<int>::iterator it = find(L[i].begin(), L[i].end(), j);
            if (it != L[i].end())
            {
                M[i][j] = 1;
                L[i].erase(it);
            }
        }
    }
    bfs();
    rep(i,n){
        printf("%d %d\n",i+1,D[i]);
    }
    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;
}

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

#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define FOR(i,n,m) for(int i=(int)(n); i<=(int)(m); i++)
#define RFOR(i,n,m) for(int i=(int)(n); i>=(int)(m); i--)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define RITR(x,c) for(__typeof(c.rbegin()) x=c.rbegin();x!=c.rend();x++)
#define setp(n) fixed << setprecision(n)

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }

#define ll long long
#define vll vector<ll>
#define vi vector<int>
#define pll pair<ll,ll>
#define pi pair<int,int>

#define all(a) (a.begin()),(a.end())
#define rall(a) (a.rbegin()),(a.rend())
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define ins insert

using namespace std;

//-------------------------------------------------
//--Graph Template
//-------------------------------------------------
template<class E>
struct Graph
{
    vector<vector<E> > adj;
    Graph(int N):adj(N){}
    virtual void add_edge(int v, E e){adj[v].push_back(e);}
    vector<E>& operator[](int v){return adj[v];}
    inline int size(){return adj.size();}
};

struct NormalEdge {
    int to;
    NormalEdge(int to):to(to){}
};

struct UWGraph : public Graph<NormalEdge>
{
    UWGraph(int N):Graph(N){}
    void add_edge(int v, int e){adj[v].push_back({e});}
};

//-------------------------------------------------
//--Dist BFS
//-------------------------------------------------
template<class E>
vector<int> distBFS(Graph<E> &G, int s)
{
    vector<int> dist(G.size(),-1); dist[s]=0;
    queue<int> que; que.push(s);
    while(!que.empty()){
        int v = que.front(); que.pop();
        for(auto e:G[v]){
            if (dist[e.to]!=-1) continue;
            dist[e.to]=dist[v]+1;
            que.push(e.to);
        }
    }
    return dist;
}

//-------------------------------------------------

int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N; cin>>N;
    UWGraph G(N);
    rep(i,N){
        int u,k; cin>>u>>k; u--;
        rep(i,k){
            int v; cin>>v; v--;
            G.add_edge(u,v);
        }
    }
    auto dist = distBFS(G,0);
    rep(i,N){
        cout<<i+1<<" "<<dist[i]<<"\n";
    }
    return 0;
}