Go: package main

/*
グラフの表現 隣接行列による表現
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		g[i] = make([]int, n+1)
		ints := eGetInts(scanner)
		num := ints[0]
		for j := 0; j < ints[1]; j++ {
			g[num][ints[j+2]] = 1
		}
	}
	dist := make([]int, n+1)
	for i := 0; i < len(dist); i++ {
		dist[i] = -1
	}
	q := []int{}

	// 訪問する
	q = append(q, 1)
	dist[1] = 0

	// キューが空でない限り
	for len(q) > 0 {
		// 先頭を取り出す
		top := 0
		top, q = q[0], q[1:]
		// 隣接マスを入れる.
		for i := 1; i < n+1; i++ {
			// 辺がある
			if g[top][i] == 1 {
				if dist[i] == -1 {
					// 訪問済みでなければ
					q = append(q, i)
					dist[i] = dist[top] + 1
				}
			}
		}
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, dist[i])
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

C++: #include <iostream>
#include <vector>
#include <list>
#include <cstdlib>

const int MAX_N = 100;

struct Node {
  int v;
  int d;
  bool visited;
};

int main(void) {
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);  

  int n = 0;
  std::cin >> n;

  std::vector<std::vector<int> *> *graph = new std::vector<std::vector<int> *>(n + 1);
  std::vector<struct Node *> *nodes = new std::vector<struct Node *>(n + 1);
  
  for (int i = 1; i <= n; i++) {
    int v = 0;
    std::cin >> v;

    int k = 0;
    std::cin >> k;

    std::vector<int> *neighbors = new std::vector<int>(k);

    for (int i = 0; i < k; i++) {
      int a = 0;
      std::cin >> a;

      neighbors->at(i) = a;
    }

    graph->at(i) = neighbors;

    struct Node *node = (struct Node *) std::malloc(sizeof(struct Node));

    node->v = i;
    node->d = -1;
    node->visited = false;
    
    nodes->at(i) = node;
  }

  int count = 0;
  int start = 1;

  //  nodes->at(start)->d = 1;

  std::list<int> *stack = new std::list<int>();

  stack->push_back(nodes->at(start)->v);

  while (!stack->empty()) {
    std::vector<int> *newNodes = new std::vector<int>();

    while (!stack->empty()) {    
      int v = stack->front();
      stack->pop_front();

      nodes->at(v)->d = count;
      nodes->at(v)->visited = true;
      
      std::vector<int> *neighbors = graph->at(v);

      for (std::vector<int>::iterator iterator = neighbors->begin(); iterator != neighbors->end(); ++iterator) {
	struct Node *node = nodes->at(*iterator);

	if (!node->visited) {
	  newNodes->push_back(node->v);
	}
      }
    }

    for (std::vector<int>::iterator iterator = newNodes->begin(); iterator != newNodes->end(); ++iterator) {
      stack->push_front(*iterator);
    }

    count++;
  }

  for (std::vector<struct Node *>::iterator iterator = nodes->begin() + 1; iterator != nodes->end(); ++iterator) {
    struct Node *node = *iterator;
        
    std::cout << node->v << " " << node->d << std::endl;
  }
  
  return 0;
}

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<stdio.h>
#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++: #include <iostream>
#include <math.h>
#include <vector>
#include <algorithm>

using namespace std;
#define MAX 105
vector<int> V[MAX];

int d[MAX];

void search(int v, int t) {
	if (d[v] == -1 || d[v] > t) d[v] = t;
	else return;

	for (int i = 0; i < V[v].size(); i++) {
		search(V[v][i], t + 1);
	}
}

int main() {


	int n;
	cin >> n;
	for (int i = 1; i < n + 1; i++) {
		d[i] = -1;

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

	search(1, 0);

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

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define clr(a,b) memset(a,b,sizeof(a))
int n;
int v,k,ttm;
vector<int> graph[105];
int dis[105];//到其他点的距离
int vis[105];//纪律顶点是否被访问
void bfs(int u)
{
    queue<int> qu;
    qu.push(u);
    dis[u]=0;
    vis[u]=1;
    while(!qu.empty())
    {
        int v=qu.front();qu.pop();
        for(int i:graph[v])
        {
            if(dis[i]||i==1){continue;}
            qu.push(i);
            dis[i]=dis[v]+1;
        }
    }
}
int main()
{
    clr(vis,0);
    cin>>n;
    for(int i=0;i<n;++i)
    {
        cin>>v>>k;
        while(k--)
        {
            cin>>ttm;
            graph[v].push_back(ttm);//连接的点
        }
    }
    bfs(1);
     cout<<1<<" "<<dis[1]<<endl;
    for(int i=2;i<=n;++i)
    {
         cout<<i<<" "<<(dis[i]?dis[i]:-1)<<endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define MAX 105
#define INFTY 10000000

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

void bfs(int s){
    //最短距離を初期化
    for(int u=1; u<=n; u++){
        d[u] = INFTY;
    }
    queue<int> Q;
    d[s] = 0;
    Q.push(s);

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

    //出力
    for(int u=1; u<=n; u++){
        if(d[u] == INFTY) printf("%d -1\n", u);
        else printf("%d %d\n", u, d[u]);
    }
}

//グラフの幅優先探索(stackを用いる)
int main(){
    cin >> n;
    //隣接リスト表現→隣接行列表現への変換
    for(int i=1; i<=n; i++){
        for(int j=1; j<=n; j++){
            M[i][j] = 0;
        }
    }
    for(int i=1; i<=n; i++){
        int u, k;
        cin >> u >> k;
        for(int j=1; j<=k; j++){
            int v;
            cin >> v;
            M[u][v] = 1;
        }
    }

    bfs(1);

    return 0;
}