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 <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <vector>
#include <queue>
using namespace std;
const int INF=1<<21;
const int maxn=100+10;
int n;
vector<int> g[maxn];
int vis[maxn];
int d[maxn];
void bfs(int s)
{
    queue<int> que;
    que.push(s);
    vis[s]=1;
    d[s]=0;
    while(!que.empty())
    {
        int u=que.front();que.pop();
        for(int i=0;i<g[u].size();i++)
        {
            int v=g[u][i];
            if(!vis[v])
            {
                que.push(v);
                d[v]=min(d[v],d[u]+1);

            }
        }
    }
}
int main()
{
//    freopen("in.txt","r",stdin);
    scanf("%d",&n);
    int no,cnt,dd;
    for(int i=0;i<n;i++)
    {
        scanf("%d%d",&no,&cnt);
        for(int j=0;j<cnt;j++)
        {
            scanf("%d",&dd);
            g[no-1].push_back(dd-1);
        }
    }
    for(int i=0;i<n;i++) d[i]=INF;
    bfs(0);
    for(int i=0;i<n;i++)
    {
        printf("%d %d\n",i+1,d[i]);
    }

    return 0;
}

C++: #include<iostream>
#include<queue>
#include<vector>
#define INF (int)1e9 + 7
using namespace std;
int n;
vector<pair<int, int> > adj[10000];
void dijkstra();
int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v; //vertex cost
            cin >> v;
            adj[u].push_back(make_pair(1, v));
        }
    }
    dijkstra();
    return 0;
}
void dijkstra() {
    int dist[n + 1];
    dist[1] = 0;
    for (int i = 2; i <= n; i++) {
        dist[i] = INF;
    }
    priority_queue<pair<int, int> > q;
    q.push(make_pair(0, 1));
    while (!q.empty()) {
        int u = q.top().second;
        //int co = -q.top().first;
        q.pop();
        for (int i = 0; i < adj[u].size(); i++) {
            int v = adj[u][i].second; //adj[u]のi番目の番号
            int co2 = adj[u][i].first;
            if (dist[u] + co2 < dist[v]) {
                dist[v] = co2 + dist[u];
                q.push(make_pair(-dist[v] ,v));
            }
        }
    }
    for (int i = 1; i <= n; i++) {
        cout << i << " " << dist[i] << endl;
    }
    
}

C++: #include<iostream>
#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<200;i++){
    k[i]=ans[i]=u[i]=-1;
  }
  
  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];
    }
  }
  
   int h;
  for(int i=0;i<n;i++){
    int Min = i;
    for(int j=i;j<n;j++){
      if(u[Min] > u[j])Min = j;
    }
    h = u[Min];
    u[Min] = u[i];
    u[i] = h;
  }
  
  Queue que = Queue();
  
  que.push(u[0]);
  ans[u[0]]=0;
  used[u[0]]=true;
  
  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;
      }
    }
  }
  //for(int i=0;i<n;i++)cout << u[i] << endl;
   
  for(int i=0;i<n;i++){
    cout << u[i] << " " << ans[u[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;
static const int N = 100;
static const int INFTY = (1<<21);

int n,M[N][N];
ind 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( void ){
  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<stdio.h>
#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){
  int i,v,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(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(i=0;i<n;i++){
    printf("%d %d\n",i+1,((d[i]==INFTY)?(-1) : d[i]));
  }
}

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

  scanf("%d",&n);

  for(i=0;i<n;i++){
    for(j=0;j<n;j++){
      M[i][j]=0;
    }
  }

  for(i=0;i<n;i++){
    scanf("%d%d",&u,&k);
    u--;
    for(j=0;j<k;j++){
      scanf("%d",&v);
      v--;
      M[u][v]=1;
    }
  }

  bfs(0);

  return 0;
}