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<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;
}