Go: package main

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

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Scan()
	num, _ := strconv.Atoi(sc.Text())
	nodes := make(map[int]*node)

	for i := 0; i < num; i++ {
		sc.Scan()
		id, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		nodeNum, _ := strconv.Atoi(sc.Text())
		n := node{id, make([]int, 0), -1}
		for j := 0; j < nodeNum; j++ {
			sc.Scan()
			nid, _ := strconv.Atoi(sc.Text())
			n.nexts = append(n.nexts, nid)
		}
		nodes[id] = &n
	}
	nodes[1].depth = 0

	walk(1, 0, &nodes)
	for i := 1; i < len(nodes)+1; i++ {
		fmt.Printf("%v %v\n", (*nodes[i]).id, (*nodes[i]).depth)
	}
}

var time int
var record [100][100]bool
var q Queue

func walk(nid int, from int, nodes *map[int]*node) {
	q.Enqueue((*nodes)[nid])
	for !q.IsEmpty() {
		n := q.Dequeue().(*node)
		for _, v := range n.nexts {
			n2 := (*nodes)[v]
			if n2.depth != -1 {
				continue
			}
			n2.depth = n.depth + 1
			q.Enqueue((*nodes)[v])
		}
	}
}

type node struct {
	id    int
	nexts []int
	depth int
}

// Queue is Queue
type Queue struct {
	val []interface{}
}

// Enqueue value
func (queue *Queue) Enqueue(val interface{}) {
	queue.val = append(queue.val, val)
}

// Dequeue value
func (queue *Queue) Dequeue() interface{} {
	res := queue.val[0]
	queue.val = queue.val[1:len(queue.val)]
	return res
}

// IsEmpty return true when queue is empty
func (queue *Queue) IsEmpty() bool {
	return len(queue.val) == 0
}

C++: #include<iostream>
#include<queue>
using namespace std;
void debug1();
int n, gragh[110][110] = {}, d[110] = {};
queue<int> q;

int main() {
	cin >> n;
	//input
	for (int i = 0; i < n; i++) {
		int u,k;
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			int t;
			cin >> t;
			gragh[u][t] = 1;
		}
	}
	//debug1();
	//search
	d[1] = 0;
	q.push(1);
	while (!q.empty()) {
		int cur = q.front();
		q.pop();
		//cerr << "visiting " << cur << " Distance: " << d[cur] << endl;
		for (int i = 1; i <= n; i++) {
			if (d[i] == 0 && gragh[cur][i] == 1 && i != 1) {
				d[i] = d[cur] + 1;
				q.push(i);
			}
		}
	}

	//from 0 to 1
	for (int i = 2; i <= n; i++) {
		if (d[i] == 0) d[i] = -1;
	}

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

void debug1() {
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			cerr << gragh[i][j] << " " ;
		}
		cerr << endl;
	}
}

C++: #include <iostream>
#include<queue>
using namespace std;
#define INF 9999999

int G[101][101];
int dis[101];
bool check[101];//訪問済みチェック
int main(){
  int n;
  cin>>n;
  for(int i=0;i<n;i++){
    int u,k;
    cin>>u>>k;
    for(int j=1;j<=k;j++){
      G[u][0]=k;
      cin>>G[u][j];
    }
  }
  fill(dis,dis+101,INF);
  dis[1]=0;
  check[1]=true;
  queue<int> Q;
  Q.push(1);
  while(!Q.empty()){
    int num=Q.front(); Q.pop();
    for(int i=1;i<=G[num][0];i++){
      int k=G[num][i];
      if(check[k])break; else check[k]=true;
      dis[k]=dis[num]+1;
      Q.push(k);
    }
  }
  for(int i=1;i<=n;i++){
    cout<<i<<" ";
    if(dis[i]==INF)cout<<-1<<"\n";
    else  cout<<dis[i]<<"\n";
  }
}

C++: #include <iostream>
using namespace std;
#define N 100
#define WHITE 0
#define BLACK 1

int M[N+1][N+1];
int n, dist;
int DIST[N+1];
int color[N+1];


//キューを使うプログラムを考える
void bfs(int r) {
    int u;
    int next[N+1], next_num = 0;
    bool added = false;
    //現時点での距離を入れておく
    for(int i=1; i<=n; i++) {
        if(M[r][i]==1 && color[i]==WHITE) {
            if(!added) {
                dist++;
                added = true;
            }
            color[i] = BLACK;
            DIST[i] = dist;
            next[next_num] = i;
            next_num++;
        }
    }
    
    for(int i=0; i<next_num; i++) {
        bfs(next[i]);
    }
}   

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

    cin >>n;
    for(int i=0; i<=n; i++) {
        DIST[i] = -1;
        color[i] = WHITE;
        for(int j=0; j<=n; j++) {
            M[i][j] = 0;
        }
    }

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

    dist = 0;
    DIST[1] = 0;
    color[1] = BLACK;
    bfs(1);

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

    return 0;
}