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<algorithm>
#include<cstdio>
#define INF 1<<30
#define MAX 100000
using namespace std;
class Queue{
private:
  int inf[MAX];
  int head,tail;
 
public:
 
  Queue(){
    syokika();
  }
 
  void syokika(){
    head = 0;
    tail = 0;
  }
 
  void push(int x){
    inf[tail]=x;
    if(MAX == tail+1)tail = 0;
    else tail++;
  }
 
  void pop(){
    if(MAX == head+1)head=0;
    else head++;
  }
 
  int front(){
    return inf[head];
  }
 
  bool empty(){
    if(tail - head == 0)return true;
    else return false;
  }
 
  int size(){
    return tail - head;
  }
 
};

int imap[200][200];
int k[200] = {0}; 
int ans[200] = {0};
bool used[200];

int main(){
  int n,u[1000];
  cin >> n;
  for(int i=0;i<200;i++)for(int j=0;j<200;j++)imap[j][i] = INF;  
  for(int i=0;i<n;i++){
    cin >> u[i];
    cin >> k[u[i]];
    for(int j=0;j<k[u[i]];j++){
      cin >> imap[u[i]][j];
    }
  }
  /*
  for(int i=0;i<n;i++){
    for(int j=0;j<k[u[i]];j++){
      cout << imap[u[i]][j] << " ";
    }
    cout << endl;
  }
  */

  Queue que = Queue();

  que.push(u[0]);

  while(!que.empty()){
    int p = que.front(); que.pop();
    for(int i=0;i<k[p];i++){
      if(!used[imap[p][i]]){
	que.push(imap[p][i]);//cout << "push!= " << imap[p][i] << endl;
	used[imap[p][i]] = true;
	ans[imap[p][i]] = ans[p] + 1;
      }
    }
  }

  sort(u,u+n);
 
  for(int i=0;i<n;i++){
    cout << u[i] << " " << ans[u[i]] << endl;
  }

  return 0;
}

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


#define MAX 100


using namespace std;


int main()
{
    vector< vector<int> > adj(MAX + 1);
    queue<int> visiting;

    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        int id, k;
        cin >> id >> k;
        for (int j = 0; j < k; j++) {
            int tmp;
            cin >> tmp;
            adj[id].push_back(tmp);
        }
    }

    vector<int> discovered(MAX + 1, -1);
    visiting.push(1);
    discovered[1] = 0;
    while (!visiting.empty()) {
        int now = visiting.front();
        visiting.pop();

        for (vector<int>::iterator it = adj[now].begin(); it != adj[now].end(); ++it) {
            if (discovered[*it] < 0) {
                discovered[*it] = discovered[now] + 1;
                visiting.push(*it);
            }
        }
    }

    for (int i = 1; i <= n; i++) {
        cout << i << " " << discovered[i] << endl;
    }

    return 0;
}

C++: #include <iostream>

using namespace std;

#define N_MAX 100

int Adj[N_MAX][N_MAX] = {};
int Min_d[N_MAX];

void bfs(int v, int d, int num_node);

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

    cin >> n;

    for (i = 0; i < n; i++) Min_d[i] = -1;

    //??£??\???????????????
    for (i = 0; i < n; i++) {
        cin >> u >> k;
        while (k-- > 0) {
            cin >> v;
            Adj[u-1][v-1] = 1;
        }
    }
/*
    cout << "show Adjacency matrix" << endl;
    for (i = 0; i < n; i++) {
        for (j = 0; j < n ; j++) {
            if (j == n - 1)
                cout << Adj[i][j] << endl;
            else
                cout << Adj[i][j] << ' ';
        }
    }
*/
    //??¢?´¢??????
    Min_d[0] = 0;
    bfs(1, 1, n);

    //????????????
    for(i = 1; i <= n; i++) {
        cout << i << ' ' << Min_d[i-1] << endl;
    }

    return 0;
}

void bfs(int v, int d, int num_node) {
    int i;
//    cout << "bfs node : " << v << endl;

    for(i = 1; i <= num_node; i++) {
        if (Adj[v-1][i-1] == 1) {
            if (Min_d[i-1] == -1 || Min_d[i-1] > d) {
                Min_d[i-1] = d;
                bfs(i, d+1, num_node);
            }
        }
    }
}

C++: #include <iostream>
#include <vector>
#include <queue>
using namespace std;
vector<int> G[110], d(110);

int main() {
    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-1].push_back(v-1);
        }
    }

    for (int i = 0; i < n; i++) d[i] = -1;

    queue<int> que;
    que.push(0);
    d[0] = 0;
    while (!que.empty()) {
        int u = que.front(); que.pop();
        for (int v: G[u]) {
            if (d[v] == -1) {
                que.push(v);
                d[v] = d[u] + 1;
            }
        }
    }

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

C++: #include <bits/stdc++.h>
typedef long long ll;
typedef unsigned long long ull;
#define reps(i,s,n) for(int (i)=(s);(i)<(n);++(i))
#define rep(i,n) reps(i,0,n)
#define reptr(i,n) for(int (i)=(n);(i)>=0;--(i))
#define All(x) (x).begin(),(x).end()
const ll MOD=1e9+7;
using namespace std;

vector<int> ans;
int state[105][105]={};
int n;
void bfs(int s){
  queue<int> q;
  q.push(s);
  while(!q.empty()){
    int u=q.front();
    q.pop();
    for(int v=0;v<n;v++){
      //隣接していない
      if(state[u][v]==false) continue;
      //既に探索されている
      if(ans[v]!=INT_MAX) continue;
      //未探索の場合
      ans[v] = ans[u]+1;
      q.push(v);
    }
  }

  rep(i,n){
    if(ans[i]==INT_MAX) ans[i] = -1;
    cout << i+1 << " " << ans[i] << endl;
  }
}

int main(){
  cin >> n;
  ans.resize(n,INT_MAX);
  ans[0]=0;
  rep(i,n){
    int u,k;
    cin >> u >> k;
    u--;
    rep(j,k){
      int v;
      cin >> v;
      v--;
      state[u][v]=1;
    }
  }
  bfs(0);
}

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

int n;

int V[100][100];
int D[100];
int d = 0;

std::queue<int> Q;

void bfs(int r) {
    Q.push(r);
    D[r] = 0;
    while (Q.size()) {
        r = Q.front();
        Q.pop();
        for (int i = 0; i < n; i++) {
            if ((D[i] == 0) && (V[r][i] == 1)) {
                Q.push(i);
                D[i] = D[r] + 1;
            }
        }
    }
}


int main() {
    std::cin >> n;
    for (int i = 0; i < n; i++) {
        int id, e_num;
        std::cin >> id >> e_num;
        for (int j = 0; j < e_num; j++) {
            int t;
            std::cin >> t;
            V[id - 1][t - 1] = 1;
        }
    }

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

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

using namespace std;
using Graph = vector<vector<int>>;

int main() {

    int n; cin >> n;
    int u, k;

    Graph G(n+1);
    for ( int i = 1; i <= n; ++i ) {
        cin >> u >> k;
        for ( int j = 1; j <= k; ++j ) {
            int a;
            cin >> a;
            G[i].push_back(a);
            //G[b].push_back(a);
        }
    }

    /*for ( int i = 1; i <= n; ++i ) {
        for ( int ax : G[i] ) {
            cout << ax ;
        }
        cout << endl;
    }*/

    vector<int> dist(n+1,-1);
    queue<int> que;

    dist[1] = 0;
    que.push(1);

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

        for ( int nv : G[v] ) {
            if ( dist[nv] != -1 ) continue;
            dist[nv] = dist[v] + 1;
            que.push(nv);
        }
    }

    for ( int i = 1; i <= n; ++i ) {
        cout << i << " " << dist[i] << endl; 
    }
}