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

using namespace std;

vector<int> graph[100];
int dist[100]={0};
int main(){
  int n;
  cin >> n;

  for(int i=0;i<n;++i){
    int u,k;
    cin >> u >> k;
    for(int i=0;i<k;++i){
      int v;
      cin >> v;
      graph[u-1].push_back(v-1);
    }
    dist[i] = -1;
  }

  queue<int> q;
  q.push(0);
  dist[0] = 0;
  while(!q.empty()){
    auto v = q.front();q.pop();
    for(auto next_v:graph[v]){
      if(dist[next_v]==-1){
        dist[next_v] = dist[v]+1;
        q.push(next_v);
      }
    }
  }
  for(int i=0;i<n;++i){
    cout << i+1 << " " << dist[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];
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 <iostream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <queue>

static const int N = 101;

using namespace std;

int main () {
  int n, v, v2, k;
  int d[N], visited[N];
  vector<vector<int> > V;
  queue<int> Q;
  int maxNumber = 1 << 21;

  for (int i = 0; i <= N; i++) {
    vector<int> A;
    V.push_back(A);
  }
  for (int i = 0; i <= N; i++) {
    d[i] = maxNumber;
    visited[i] = 0;
  }

  cin >> n;

  for (int i = 0; i < n; i++) {
    cin >> v >> k;

    for (int j = 0; j < k; j++) {
      cin >> v2;
      V[v].push_back(v2);
    }
  }

  Q.push(1);
  d[1] = 0;

  while (Q.size()) {
    for (vector<int>::iterator it = V[Q.front()].begin(); it != V[Q.front()].end(); it++) {
      if (!visited[*it]) {
        Q.push(*it);
        //printf("d[%d] = d[%d] + 1\n", *it, Q.front());
        d[*it] = min(d[*it], d[Q.front()] + 1);
        visited[*it] = 1;
      }
    }

    Q.pop();
  }

  for (int i = 1; i <= n; i++)
    cout << i << " " << (d[i] == maxNumber ? -1 : 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];

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<iostream>
#include<queue>
using namespace std;
int N;
int D[101],d[101][101];
void bfs(int src){
    int u[101],k[101],a[101];
    bool visit[101];
    for(int i=1;i<=N;++i){
        cin>>u[i]>>k[i];
        for(int j=0;j<k[i];++j){
            cin>>a[j];
            d[u[i]][a[j]]=1;
        }
        visit[i]=true;
    }
    queue<int>Q;
    Q.push(src);
    D[src]=0;
    visit[src]=false;
    while(!Q.empty()){
        int cur=Q.front();
        Q.pop();
        for(int i=1;i<=N;++i){
            if(d[cur][i]==1&&visit[i]){
                visit[cur]=false;
                visit[i]=false;
                D[i]=D[cur]+1;
                Q.push(i);
            }
        }
    }
    for(int i=1;i<=N;++i){
        if(i!=1&&D[i]==0){
            D[i]=-1;
        }
        cout<<i<<" "<<D[i]<<endl;
    }
}
int main(){
    cin>>N;
    int start=1;
    bfs(start);
}

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <stdlib.h>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
#define max 101
#define INF -1
#define WHITE 0
#define GRAY -1
#define BLACK 1
int n,color[max],d[max];
int varry[max][max];
void bfs(int s){
  queue<int>q;
  int u;
  for(int i=1;i<=n;i++){
    d[i]=INF;
  }
  color[s]=GRAY;
  d[s]=0;
  q.push(s);
  while(!q.empty()){
    u=q.front();
    q.pop();
    for(int i=1;i<varry[u][0]+1;i++){
      if(color[varry[u][i]]==WHITE){
	color[varry[u][i]]=GRAY;
	d[varry[u][i]]=d[u]+1;
	q.push(varry[u][i]);
      }
    }
    color[u]=BLACK;
  }

}
int main(){
  int u;
  cin>>n;
  for(int k=0;k<n;k++){
    cin>>u;
    cin>>varry[u][0];
    for(int i=0;i<varry[u][0];i++)
      cin>>varry[u][i+1];
  }
  bfs(1);
  for(int i=1;i<=n;i++)
    cout<<i<<" "<<d[i]<<endl;


  return 0;
}

C++: // ALDS1_11_C
#include <bits/stdc++.h>
#define endl "\n"
#define rep(i,n) for(int i=0;i<int(n);i++)
#define SZ(x) ((int)(x).size())
#define all(x) (x).begin(),(x).end()
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ipair;
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;}
namespace you {
    std::string to_string(char val) {
        return std::string(1, val);
        // return std::string{val};
        // you::to_string(char)
    }
}

vector<int> d(110,-1);
vector<vector<int>> to(110);
vector<int> setu(110,0);
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(12);

    int n;
    cin>>n;
    rep(i,n){
        int u,k;
        cin>>u>>k;
        setu[u]=k;
        rep(j,k){
            int q;
            cin>>q;
            to[u].emplace_back(q);
        }
    }
    queue<int> next;
    next.push(1);
    d[1]=0;
    while(!next.empty()){
        int cur=next.front();
        next.pop();
        for(int i=0;i<setu[cur];i++){
            int t=to[cur][i];
            //１に近いところから見ているので、もし距離が更新されているならそれ以上距離が短くなることはない。
            //よって、そのnodeからの探索はしなくていい。a⇔bのときに無限ループしちゃう。
            if(d[t]!=-1) continue; 
            d[t]=d[cur]+1;
            next.push(t);
        }
    }
    for(int i=1;i<=n;i++){
        cout<<i<<" "<<d[i]<<endl;
    }
    return 0;
}