Go: package main

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

const MAX = 1000
const NIL = -1

type Node struct {
	id    int
	depth int
}

type Queue struct {
	head      int
	tail      int
	container [MAX]Node
}

func (q *Queue) inQueue(x Node) {
	q.container[q.tail] = x
	q.tail = (q.tail + 1) % MAX
}

func (q *Queue) deQueue() Node {
	x := q.container[q.head]
	q.head = (q.head + 1) % MAX
	return x
}

func (q *Queue) isEmpty() bool {
	return q.head == q.tail
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()
	route := make([][]int, n)
	for i := range route {
		u, k := scanInt(), scanInt()
		u--
		route[u] = make([]int, k)
		for j := range route[u] {
			num := scanInt()
			num--
			route[i][j] = num
		}
	}

	d := make([]int, n)
	for i := range d {
		d[i] = NIL
	}

	start := Node{0, 0}
	que := Queue{}
	que.inQueue(start)
	for !que.isEmpty() {
		node := que.deQueue()
		if d[node.id] != NIL {
			continue
		}
		d[node.id] = node.depth

		for _, nextId := range route[node.id] {
			next := Node{id: nextId, depth: node.depth + 1}
			que.inQueue(next)
		}
	}

	for i, depth := range d {
		fmt.Println(i+1, depth)
	}
}

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

using namespace std;

#define MAX 100

#define WHITE 0
#define GRAY 1
#define BLACK 2

int T;
int N;

int M[MAX][MAX];
int C[MAX],D[MAX];

void bfs(int s)
{
    stack<int> *q = new stack<int>;

    q->push(s);
    D[s] = 0;
    C[s] = GRAY;

    while(!q->empty())
    {
        int u = q->top();
        q->pop();

        for (int v = 0; v < N; v++)
        {
            if (M[u][v] && C[v] == WHITE)
            {
                C[v] = GRAY;
                D[v] = D[u] + 1;
                q->push(v);
            }
        }

        C[u] = BLACK;
    }
}

int main ()
{
    cin >> N;

    for (int i = 0; i < N; i++)
    {
        C[i] = WHITE;
        D[i] = -1;

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

    for (int i = 0; i < N; i++)
    {
        int u, k;
        cin >> u >> k;
        u--;

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

/*
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            if (j > 0)
                cout << " ";
            cout << M[i][j];
        }
        cout << endl;
    }
*/
    bfs(0);

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

    return 0;
}

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

int D[100];
int a[100][100];

int main() {
  for (int i = 0; i < 100; i++){
    for (int j = 0; j < 100; j++){
	  a[i][j] = 0;
	  }
	 }
	int n,u,k,v;
	cin >> n;
	for (int i = 0; i < n; i++) {
	  cin >> u >> k;
	  for (int j = 0; j < k; j++) {
	    cin >> v;
		a[u][v] = 1;
		}
	  }
queue<int> Q; //整数を管理するキューの定義
  for (int i = 1; i < n+1; i++){
   D[i] = -1;
   }
  int src = 1;
  Q.push(src);
  D[src] = 0; //出発点
  while (! Q.empty()) {
    int cur = Q.front(); //先頭要素を取り出す
	Q.pop();
	//動作確認用表示
	cerr << "visiting " << cur << ' ' << D[cur] << endl;
	for(int dst = 1 ; dst <= n; dst++) { //各行き先dstに対して
	if((a[cur][dst] == 1 && D[dst] == -1)) { //curからdstに辺があり、dstが未訪問なら
	      D[dst] = D[cur] + 1; //
		    Q.push(dst); //dstを訪問先に入れる
			}
		  }
		}
	for (int i=1; i < n+1; i++){
	  cout << i << " " << D[i] << endl;
	  }
	}