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 <algorithm>
#include <iostream>
#include <vector>
#include <queue>
using namespace std;

//---------------------------------------------------------------
// ------ graph ------ //
using Weight = int;
using Flow = int;
struct Edge {
    int src, dst;
    Weight weight;
    Flow cap;
    Edge() : src(0), dst(0), weight(0) { }
    Edge(int s, int d, Weight w) : src(s), dst(d), weight(w) { }
};
bool operator < (const Edge &e, const Edge &f) {
    return e.weight != f.weight ? e.weight > f.weight : // pqが降順のため
        e.src != f.src ? e.src < f.src : e.dst < f.dst;
}
using Edges = vector<Edge>;
using Graph = vector<Edges>;
using Array = vector<Weight>;
using Matrix = vector<Array>;
void add_edge1(Graph &g, int a, int b, Weight w = 1) {
    g[a].emplace_back(a, b, w);
}
void add_edge2(Graph &g, int a, int b, Weight w = 1) {
    g[a].emplace_back(a, b, w);
    g[b].emplace_back(b, a, w);
}
void add_arc(Graph &g, int a, int b, Weight w = 1) {
    g[a].emplace_back(a, b, w);
}
//---------------------------------------------------------------

vector<int> bfs(int src, Matrix &M) {
    int n = M.size();
    vector<int> dist(n, -1);
    queue<int> Q;
    dist[src] = 0;
    Q.push(src);
    while (!Q.empty()) {
        int cur = Q.front(); Q.pop();
        for (int nxt = 0; nxt < n; nxt++) {
            if (M[cur][nxt] && dist[nxt] < 0) {
                dist[nxt] = dist[cur] + 1;
                Q.push(nxt);
            }
        }
    }
    return dist;
}

int main() {
    int n; cin >> n;
    Matrix M(n, Array(n, 0));
    for (int i = 0; i < n; i++) {
        int u, k; cin >> u >> k;
        while (k--) {
            int v; cin >> v; M[u - 1][v - 1]++;
        }
    }
    vector<int> dist = bfs(0, M);
    for (int i = 0; i < n; i++) {
        cout << i + 1 << " " << dist[i] << endl;
    }
    return 0;
}

C++: //16D8103013E Sen Shunkou
#include<iostream>
#include<queue>
int n;
int cnt=0;

int main(){
    //input
    int n;
    std::cin>>n;

    int cnt=0;
    int A[100][100];
    int dis_min[n];
    bool visited[n];

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

    for(int i=0;i<n;i++){
        std::cin>>A[i][0];
        std::cin>>A[i][1];
        for(int j=0;j<A[i][1];j++){
            std::cin>>A[i][j+2];
        }
    }

    for(int i=0;i<n;i++){
        dis_min[i]=-1;
    }

    //initialization
    std::queue<int> que;
    que.push(0);
    //std::cout<<"\n"<<que.front()<<"\n";
    //std::cout<<que.size()<<"\n\n";

    while(!que.empty()){
        int q=que.size();
        for(int k=0;k<q;k++){
            //std::cout<<"quesize"<<que.size()<<"\n";
            int i=que.front();
            que.pop();
            visited[i]=true;
            dis_min[i]=cnt;
            //std::cout<<i<<"cnt"<<cnt<<"\n";
            if(A[i][1]!=0){
                for(int j=0;j<A[i][1];j++){
                    if(visited[A[i][j+2]-1]!=true){
                        visited[A[i][j+2]-1]=true;
                        que.push(A[i][j+2]-1);
                        //std::cout<<A[i][j+2]-1<<"\n";
                    }
                }
            }
        }
        cnt++;
        //std::cout<<"cnt="<<cnt<<"\n";
    }

    //std::cout<<"===========\n";

    //output
    for(int i=0;i<n;i++){
        std::cout<<i+1<<' '<<dis_min[i]<<std::endl;
    }

    return 0;
}

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

const int inf = 1<<29;
int n;
vector<int> d(110, inf);
vector< vector<bool> > G(110, vector<bool>(110, false));

void bfs(int s){

    queue<int> q;
    d[s] = 0;
    q.push(s);

    while(!q.empty()){
        int now = q.front(); q.pop();
        for(int i=1; i<=n; ++i){
            if(G[now][i] == true && d[now]+1 < d[i]){
                d[i] = d[now] + 1;
                q.push(i);
            }
        }
    }

}

int main(){
    cin >> n;

    for(int i=0; i<n; ++i){
        int id, k; cin >> id >> k;
        for(int j=0; j<k; ++j){
            int v; cin >> v;
            G[id][v] = true;
        }
    }

    bfs(1);

    for(int i=1; i<=n; ++i){
        cout << i << " ";
        if(d[i] == inf) cout << -1;
        else cout << d[i];
        cout << endl;
    }
}

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

#define N 1000
#define UNDEFINED -1

int n, u, k, v;
int G[N][N];
std::queue<int> Q;
int d[N];

int main() {
    for(int i = 0; i < N; i++) {
        d[i] = UNDEFINED;
        for(int j = 0; j < N; j++) {
            G[i][j] = 0;
        }
    }

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

    d[1] = 0;
    Q.push(1);
    while(!Q.empty()) {
        int q = Q.front();
        Q.pop();
        for(int i = 1; i <= n; i++) {
            if(G[q][i] != 0 && d[i] == UNDEFINED){
                d[i] = d[q] + 1;
                Q.push(i);
            }
        }
    }

    for(int i = 1; i <= n; i++) {
        printf("%d %d\n", i, d[i]);
    }

    return 0;
}