Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

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

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	n := len(list)
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list[0 : n-1] {
		buf.Write([]byte(fmt.Sprintf("%d ", v)))
	}
	buf.Write([]byte(fmt.Sprintf("%d\n", list[n-1])))
	buf.Flush()
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

//solve
const INFTY = (1 << 21)
const MAX = 100
const WHITE = 0
const GRAY = 1
const BLACK = 2

var time, n int

//隣接行列
var M [MAX][MAX]int

//d[i]: 頂点1から頂点iまでの距離
var color, d [MAX]int

func bfs(s int) {
	var q []int
	q = append(q, s)
	for i := 0; i < n; i++ {
		d[i] = INFTY
	}
	//sは開始点なので、0をいれる
	d[s] = 0

	//キューが空になるまで、以下を繰り返す
	for len(q) > 0 {
		u := q[0]
		q = q[1:]
		for v := 0; v < n; v++ {
			if M[u][v] == 0 {
				continue
			}
			if d[v] != INFTY {
				continue
			}
			d[v] = d[u] + 1
			q = append(q, v)
		}
	}

	for i := 0; i < n; i++ {
		fmt.Printf("%d ", i+1)
		if d[i] == INFTY {
			fmt.Printf("%d\n", -1)
		} else {
			fmt.Printf("%d\n", d[i])
		}
	}
}

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 0; i < n; i++ {
		u, k := nextInt(), nextInt()
		M[u-1][u-1] = 0

		//fmt.Println(u, k)
		if k > 0 {
			for j := 0; j < k; j++ {

				v := nextInt()
				M[u-1][v-1] = 1

			}
		}

	}

	bfs(0)

}

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

static const int N = 100;
//static const int white = 0;
//static const int gray = 1;
//static const int black = 2;
static const int inf = (1 << 30);

int n, m[N][N];
int d[N];
//color[N];

void bfs(int s) {
	queue<int> q;
	for (int i = 0; i < n; i++) {
		//color[i] = white;
		d[i] = inf;
	}
	d[s] = 0;
	q.push(s);
	//color[s] = gray;
	while (!q.empty()) {
		for (int  i = 0; i < n; i++) {
			if (m[s][i] == 1 && d[i] == inf) {
				q.push(i);
				d[i] = d[s] + 1;
			}
		}
	//	color[s] = black;
		q.pop();
		s = q.front();
	}
}

int main() {
	cin >> n;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			m[i][j] = 0;
		}
	}	
	int u, k, v;
	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);
	for (int i = 0; i < n; i++) {
		if (d[i] == inf)
			cout << i + 1 << " " << -1 << endl;
		else
			cout << i + 1 << " " << d[i] << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#define NODE_SIZE 101
#define NIL -1

using namespace std;

int adj[NODE_SIZE][NODE_SIZE];
int depth[NODE_SIZE];
int n, d;

void bfs(int node, int parent){
    depth[node] = depth[parent] + 1;
    for(int i = 1; i <= n; i++){
        if(adj[node][i] && (depth[i] == NIL || depth[i] > depth[node] + 1)){
            bfs(i, node);
        }
    }
}

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

    cin >> n;
    for(int i = 0; i < n; i++){
        cin >> u >> k;
        depth[u] = NIL;
        while(k--){
            cin >> v;
            adj[u][v] = 1;
        }
    }


    depth[0] = NIL;
    bfs(1, 0);
    for(int i = 1; i <= n; i++){
        cout << i << " " << depth[i] << endl;
    }

    return 0;
}

C++: #include <iostream>
#include <cstring>
#include <cstdlib>
#include <sstream>
#include <stack>
#include <queue>
#include <list>
#include <stdio.h>
#include <algorithm>
#define MAX 100000
using namespace std;
typedef long long ll;
int map[255][255];
int d[255];
bool vis[255];
void bfs(int n,int pos,int distance)
{
	int a[255],j=0;
	vis[pos]=true;
	for(int i=1;i<=n;i++)
	{
		if(map[pos][i]&&!vis[i]){
			a[j++]=i;
			vis[i]=true;
			d[i]=distance;
		} 
	}
	for(int i=0;i<j;i++)
	{
		bfs(n,a[i],distance+1);
	}
}
int main()
{	
	int n;
	cin>>n;
	for(int i=1;i<=n;i++)
		for(int j=1;j<=n;j++)
		{
			map[i][j]=0;
		}
	for(int i=0;i<n;i++)
	{
		int cur,k,u;
		cin>>cur>>k;
		while(k--)
		{
			cin>>u;
			map[cur][u]=1;
		}
	}
	for(int i=1;i<=n;i++)
	{
		vis[i]=false;
		d[i]=-1;
	}
	d[1]=0;
	bfs(n,1,1);
	for(int i=1;i<=n;i++)
	{
		cout<<i<<" "<<d[i]<<endl;
	}
	return 0;
}

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

int D[100];
int mat[100][100];

void bfs(int src);

int main() {
  int n;
  for (int i=0;i<100;++i) {
    for (int j=0;j<100;++j)
      mat[i][j] = 0;
    D[i] = -1;
  }
  cin >> n;
  for (int i=0;i<n;++i) {
    int buf1,buf2;
    cin >> buf1 >> buf2;
    for (int j=0;j<buf2;++j) {
      int buf3;
      cin >> buf3;
      mat[i][buf3-1] = 1;
    }
  }
  bfs(0);
  for (int i=0;i<n;++i)
    cout << i+1 << " " << D[i] << endl;
}

void bfs(int src) {
  // cout << "bfs root = " << src << endl;
  queue<int> Q; // 整数を管理するキューの定義
  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
    // cout << "visiting " << cur << " " << D[cur] << endl;
    for (int dst=0;dst<100;++dst) { // 各行き先 dst に対して
      if (mat[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 を訪問先に加える
      }
    }
  }
}

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

using namespace std;
struct node
{
    node() {};
    node(int i, int n, int* xs) : id {i}, ns {vector<int>(xs, xs+n)}, d {-1} {};
    int id;
    vector<int> ns;
    int d;
};

void bfs(node* xs, int n, int st)
{
    queue<int> que {};
    bool used[n+1] {false};
    que.push(st);
    xs[st].d = 0;
    used[st] = true;
    while(que.size())
    {
        int p = que.front();
        que.pop();
        vector<int> ns = xs[p].ns;
        for(auto x : ns)
        {
            if(used[x])
            {
                continue;
            }
            xs[x].d = xs[p].d + 1;
            used[x] = true;
            que.push(x);
        }
    }
}

int main()
{
    int n;
    cin >> n;
    node graph[n+1];
    for(int i = 0; i < n; ++i)
    {
        int id;
        int m;
        cin >> id >> m;
        int xs[m];
        for(int j = 0; j < m; ++j)
        {
            cin >> xs[j];
        }
        graph[id] = node(id, m, xs);
    }
    bfs(graph, n, 1);
    for(int i = 1; i <= n; ++i)
    {
        cout << i << ' ' << graph[i].d << endl;
    }
}

C++: #include <stdio.h>
#include <string.h>
#include<iostream>
#include<queue>
using namespace std;

char s[13][1];
int D[102][102];
int A[103],f[103],w,h,n,sx,sy,gx,gy,e,g[103];
int   kensa(int ,int);
int main(){
	queue<int> P;
	int i,j,a,b,c,d;
	for(i=0;i<100;i++){
		for(j=0;j<100;j++){
			D[i][j]=-1;		
		}					
	}						
	for(i=0;i<100;i++){		
		A[i]=0;				
		f[i]=-1;
		g[i]=0;
	}							
	scanf("%d" ,&a);//     a=4
	for(i=1;i<=a;i++){
        scanf("%d",&b);		//
		scanf("%d",&b);			//b=2					//
		for(j=1;j<=b;j++){		//
		scanf("%d",&c);			//					//
		D[i][c]=1;
//
		}						//D[???][???]
	}				
	for(i=1;i<=a;i++){
		for(j=1;j<=a;j++){
		//	printf("%d %d %d\n",i,j,D[i][j]);
		}	
	}//
	P.push(1);
	//P???1
	f[1]=0;
	while(!P.empty()){			//
		d=P.front();
		//
		A[d]=1;
		//
		P.pop();				//
		for(i=1;i<=a;i++){
			//printf("%d %d %d\n",d,i,D[d][i]);//
			if(D[d][i]==-1){		//
			continue;			//
			}					//
			if(A[i]==1){		//
			continue;			//
			}					//
			P.push(i);			//
			f[i]=g[d]+1;
			g[i]=g[d]+1;
			A[i]=1;
			//printf("%d\n",P.back());
		}	
	}							//
	for(i=1;i<=a;i++){			//
	printf("%d %d\n",i, f[i]);	//
	}
	return 0;
}