Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)

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

		d[i+1] = -1
	}

	q := [][]int{}
	q = append(q, []int{1, 0})
	for len(q) > 0 {
		pop := q[0]
		if len(q) > 1 {
			q = q[1:]
		} else {
			q = [][]int{}
		}
		if d[pop[0]] >= 0 {
			continue
		}
		d[pop[0]] = pop[1]

		for j := 0; j < len(g[pop[0]]); j++ {
			q = append(q, []int{g[pop[0]][j], pop[1]+1})
		}
	}

	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d\n", i, d[i])
	}
}

C++: //push(),pop():C++ではstackと統一されいる
//front():先頭の要素が何かを返す
//back():末尾の要素が何であるかを返す
//empty():キューが空であるかどうかを調べる
//size():要素数を調べる
#include <iostream>
#include <queue>
using namespace std;
#define MAX 101
#define WHITE 0
#define GRAY 1
#define BLACK 2
static const int INFTY = (1<<21);

int G[MAX][MAX],color[MAX],d[MAX],num;

void bfs(int s){
  int u;
  queue<int> Q; //Qを使うことでエンキュー、デキューの操作が容易になる
  for(int i=1; i<=num; i++) {
    d[i] = INFTY;
  }
  Q.push(s);
  d[s] = 0;
  while(!Q.empty()){
    u = Q.front();
    Q.pop();
    for(int v=1; v<=num; v++){
      if(G[u][v] == 0) continue;
      if(d[v] != INFTY) continue;
      d[v] = d[u] + 1;
      Q.push(v);
    }
  }
}


int main(){
  int i,j,u,k,v;

  scanf("%d",&num);
  for(i=1; i<=num; i++){
    color[i] = WHITE;
    for(j=1; j<=num; j++){
      G[i][j] = 0;
    }
  }
  for(i=1; i<=num; i++){
    scanf("%d%d",&u,&k);
    for(j=1; j<=k; j++){
      scanf("%d",&v);
      G[u][v] = 1;
    }
  }

  bfs(1);

  for(i=1; i<=num; i++) printf("%d %d\n",i,d[i]);

  return 0;
}

C++: #define _GLIBCXX_DEBUG

#include"bits/stdc++.h"
using namespace std;

//loops
#define REP(i,n) for(int i=0;i<(ll)(n);i++)
#define REPD(i,n) for(int i=(ll)(n)-1;i>=0;i--)
#define OneToN(i,n) for(int i=1;i<(ll)(n+1);i++)
#define ZeroToN(i,n) for(int i=0;i<(ll)(n+1);i++)
#define AToB(i,a,b) for(int i=a;i<(ll)(b+1);i++)
#define FOR(i,a,b) for(int i=(a);i<=(b);i++)
#define FORD(i,a,b) for(int i=(a);i>=(b);i--)

//bitsearch
#define BITSEARCH(bit, n) for (int bit = 0; bit < (1<<n); ++bit)
#define isOne(bit, i) bit & (1<<i)


//arrays
#define ALL(x) (x).begin(),(x).end() //sortなどの引数を省略したい
#define SIZE(x) ((ll)(x).size()) //sizeをsize_tからllに直しておく
#define add push_back


#define remove_unique(v) v.erase(unique(ALL(v)), v.end())

//pair
#define fir first
#define sec second

//types
#define ll long long
#define vec vector
#define cord2d pair<int,int>
//UNCOMMENT WHEN NEEDED
//#define int ll

//input
template <class T> T get(){ T s; cin >> s; return(s);}
#define gi get<int>()
#define gs get<string>()

template <class T> vector<T> getv(int n) { vec<T> v(n); REP(i, n) cin >> v[i]; return v; }
#define gim(n) getv<int>(n)
#define gsm(n) getv<string>(n)

//output
void print(int a){ cout << a << endl; }
void print(long long a){ cout << a << endl; }
void print(string a){ cout << a << endl; }
void print(char a){ cout << a << endl; }
void print(double a){ cout << a << endl; }
void print(double a, int dig){ cout << std::setprecision(dig) << a << endl; }

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;}

template <class T = int>
void print(vec<T> v){ cout << v << endl; }

template <class T = int>
void print2dVec(vec<vec<T>> v2d){for(vec<T> v: v2d) {print(v);}}

void YesNo1(bool i = true){ return print(i?"Yes":"No"); }
void YESNO2(bool i = true){ return print(i?"YES":"NO"); }

//debug output
#define var_name(var) #var
template <class T> void debug(T &var, int nest = 0, string before = "") { cout << string("          ", nest) << before; print(var); }

//name replacement
#define y0 y0__
#define y1 y1__
#define j0 j0__
#define j1 j1__

//bool lambdas
#define lamb(exp) [](auto i){return exp;}
#define isEven [](int i){return i % 2 == 0;}
#define isOdd [](int i){return i % 2 != 0;}

//constants
const ll INF = 1e18;
const int MOD = 10000007;

//maths
int factorial(int k){ int sum = 1; for (int i = 1; i <= k; ++i) { sum *= i; } return sum; }
int gcd(int a, int b) {
    if (b == 0)
        return a;
    return gcd(b, a % b);
}

////////////////////

void Main() {
    //code here

    int n = gi;
    vec<vec<int>> graph(n);
    REP(i, n) {
        //print(i);
        int u = gi;
        int k = gi;
        REP(j, k) {
            graph[u-1].add(gi-1);
        }
    }

    //幅優先探索
    // BFS のためのデータ構造
    vector<int> dist(n, -1); // 全頂点を「未訪問」に初期化
    queue<int> que;

    // 初期条件 (頂点 0 を初期ノードとする)
    dist[0] = 0;
    que.push(0); // 0 を橙色頂点にする

    // BFS 開始 (キューが空になるまで探索を行う)
    while (!que.empty()) {
        int v = que.front(); // キューから先頭頂点を取り出す
        que.pop();

        // v から辿れる頂点をすべて調べる
        for (int nv : graph[v]) {
            if (dist[nv] != -1) continue; // すでに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てキューに追加する
            dist[nv] = dist[v] + 1;
            que.push(nv);
        }
    }

    REP(i, n) {
        cout << i+1 << " " << dist[i] << endl;
    }
}

signed main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    Main();
}

C++: #include <iostream>
#include <queue>
#include <vector>
using namespace std;
int d[128][128],solve[128];
int main(){
      //input
      int n,m,row,t;
      queue<int> que;
      cin >> n;
      for(int i= 0;i<n;i++){
            cin >>row>>m;
            for(int j = 0;j<m;j++){
                  cin>>t;
                  d[row][t] = d[t][row] = 1;
            }
      }
      //debug
      //for(int i = 0;i<=n;i++){
      //for(int j = 0;j<=n;j++)cout << d[i][j] << ' ';cout << endl;}

      //solve
      fill(solve,solve+n+2,-1);
      que.push(1);
      solve[1] = 0;
      while(!que.empty())
      {
            int p = que.front();
            que.pop();
            for(int i = 1;i<=n;i++)
            {
                  if(d[p][i] && solve[i]==-1)
                  {
                        que.push(i);
                        solve[i] = solve[p] + 1;
                  }
            }
      }
      for(int i = 1;i<=n;i++)
            cout << i << ' '<< solve[i]<<endl;


}

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

using namespace std;
static const int N = 100;
static const int INFTY = (1<<21);

int n, m[N][N], d[N];

void bfs(int s){
  int i, j, u;

  queue<int> q;
  q.push(s);

  for(i = 0 ; i < n ; i++) d[i] = INFTY;

  d[s] = 0;

  while(!q.empty()){
    u = q.front();
    q.pop();

    for(j = 0 ; j < n ; j++){
      if(m[u][j] == 0) continue;
      if(d[j] != INFTY) continue;
      d[j] = d[u] + 1;
      q.push(j);
    }
  }
  for(i = 0 ; i < n ; i++){
    cout << i+1 << " " << ( (d[i] == INFTY) ? (-1) : d[i] ) << endl;
  }
}


int main(){
  int i, j, u, k, v;

  cin >> n;
  for(i = 0 ; i < n ; i++){
    for(j = 0 ; j < n ; j++) m[i][j] = 0;
  }

  for(i = 0 ; i < n ; i++){
    cin >> u >> k;
    u--;
    for(j = 0 ; j < k ; j++){
      cin >> v;
      v--;
      m[u][v] = 1;
    }
  }

  bfs(0);

  return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;

static const int N=100;
static const int NIL=-1;

int n,M[N][N],d[N];

int main(){
    int i,j,u,k,v;
    cin>>n;
    for(i=0;i<n;i++){
        for(j=0;j<n;j++){
            M[i][j]=0;
        }
        d[i]=NIL;
    }
    for(i=0;i<n;i++){
        cin>>u>>k;
        u--;
        for(j=0;j<k;j++){
            cin>>v;
            M[u][--v]=1;
        }
    }

    queue<int> Q;
    Q.push(0);
    d[0]=0;
    while(!Q.empty()){
        int u=Q.front();Q.pop();
        for(int v=0;v<n;v++){
            if(M[u][v]&&d[v]==NIL){
                Q.push(v);
                d[v]=d[u]+1;
            }
        }
    }

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