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 "taichitary.h"
#define V_MAX 100

int m[V_MAX][V_MAX];
int cnt[V_MAX];
int count=0;
int n;

void bfs(int u){

    queue<int> Q;
    Q.push(u);
    cnt[u] = 0;
    int v = Q.front();

    while(!Q.empty()){

        for(int i=0; i<n; i++){
            if(m[v][i] == 1 && cnt[i] == -1){
                Q.push(i);
                cnt[i] = cnt[v]+1;
            }
        }

        Q.pop();
        v = Q.front();
    }
}


int main(){

    cin >> n;

    int from, deg;

    for(int i=0; i<n; i++){
        cin >> from >> deg;
        from--;
        for(int j=0; j<deg; j++){
            int tmp;
            cin >> tmp;
            tmp--;
            m[from][tmp] = 1;
        }
    }

    for(int k=0; k<n; k++) cnt[k] = -1; //?????????

    bfs(0);

    for(int j=0; j<n; j++){
        cout << j+1 << " " << cnt[j] << endl;
    }


}

C++: from collections import deque
n = int(input())
A = [0]*(n+1)
D = [-1]*(n+1)
DP = [0]*(n+1)
d = deque()
for i in range(n):
    A[i+1] = [int(i) for i in input().split()]
d.append(1)
D[1] = 0
DP[1] = 1
while(len(d)>0):
    tmp = d.pop()
    for i in A[tmp][2:]:
        if not DP[i]:
            D[i] = D[tmp]+1
            DP[i] = 1
            d.appendleft(i)
for i in range(1,n+1):
    tmp = "{} {}".format(i,D[i])
    print(tmp)

C++: //Breadth First Search
#if 0
?????¨?????????30??????
??????????????¨??????????????¢?´¢????????¬????????¨??¢?????´????????????????£?
#endif
#include<iostream>
#include<vector>
#include<queue>
using namespace std;
int n;
int D[100];
int matrix[100][100];
void bfs(int src)
{
    //cerr<<"bfs root = "<<src<<endl;
    queue<int> q;
    q.push(src);
    D[src]=0;
    while(!q.empty())
    {
        int cur=q.front();
        q.pop();
        //cerr<<"visiting "<<cur<<' '<<D[cur]<<endl;
        for(int dst=0;dst<n;dst++)
        {
            if(matrix[cur][dst]==1&&D[dst]==-1)
            {
                D[dst]=D[cur]+1;
                q.push(dst);
            }
        }
    }
};

int main()
{
    vector<int> l[101];
    cin>>n;
    for(int i=0;i<n;i++)
    {
        int u,k;
        cin>>u>>k;
        for(int j=0;j<k;j++)
        {
            int tmp;
            cin>>tmp;
            l[u].push_back(tmp);
        }
    }
    
    for(int i=0;i<100;i++)
    {
        D[i]=-1;
    }
    
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)
        {
            matrix[i][j]=0;
        }
    }
    
    for(int i=1;i<n+1;i++)
    {
        for(int j=0;j<l[i].size();j++)
        {
            matrix[i-1][l[i][j]-1]=1;
        }
    }
    
    bfs(0);
    
    for(int i=0;i<n;i++)
    {
        cout<<(i+1)<<' '<<D[i]<<endl;
    }
}

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

using namespace std;
static const int N = 100;
static const int INFTY = (1<<21); // ?????????????????????(2^21)

int n,M[N][N];
int d[N]; // ?????¢??§?¨??????¶???(color)???????????????

void bfs(int s){
	queue<int> q; // ?¨??????????????????????queue????????¨
	q.push(s);
	for(int i=0;i<n;i++) d[i] = INFTY; // ???????????????????????§??°?????\?????????
	d[s] = 0;
	int u;
	while(!q.empty()){
		u = q.front(); q.pop(); // ?????\???????????????u???????????????
		for(int v=0;v<n;v++){
			if(M[u][v] == 0) continue; // ??????u????????????v??????????????????????????°??????
			if(d[v] != INFTY) continue; // ??????v????????§????¨???????????????¨???????????°??????
			d[v] = d[u] + 1; // ??????v????????????u?????°?????????+1?????°??????????????\?????????
			q.push(v); // ?????\????????????v?????\??????
		}
	}
	for(int i=0;i<n;i++){
		cout << i+1 << " " << ((d[i] == INFTY) ? (-1) : d[i]) << endl; // ??????i?????°????????????INFTY??????-1???????????\???????????°????????????????????????
	}
}

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

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

	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);

	return 0;
}

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

int n;
int d[101];
bool a[101][101];
const int INF = (1<<21);

void bfs(int s)
{
    queue<int> q;
    q.push(s);
    for(int i=0; i<n; i++) d[i] = INF;
    d[s] = 0;
    
    int u;
    while(!q.empty())
    {
        int u = q.front();
        q.pop();
        for(int v=0; v<n; v++)
        {
            if(a[u][v] && d[v] == INF)
            {
                d[v] = d[u] + 1;
                q.push(v);
            }
        }
    }
}


int main() {
    ios::sync_with_stdio(false);
    cin >> n;
    for(int i=0; i<n; i++)
    {
        for(int j=0; j<n; j++)
        {
            a[i][j] = false;
        }
    }

    for(int i=0; i<n; i++)
    {
        int u, k;
        cin >> u >> k;
        for(int j=0; j<k; j++)
        {
            int v;
            cin >> v;
            a[u-1][v-1] = true;
        }
    }
    
    bfs(0);

    for(int i=0; i<n; i++)
    {
        cout << i+1 << " " << ((d[i] == INF) ? (-1) : d[i]) << endl;
    }
    return 0;
}