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 <iostream>
#include <algorithm>
#include <string>
#include <stack>
#include <cstdlib>
#include <queue>
#include <vector>
#include <set>
#include <stdio.h>
using namespace std;
int n,m,l,p;
int a[100][100];
int D[100];
void bfs( int src) {
	queue<int> Q;
	Q.push(src);
	D[src]=0;
	while( ! Q.empty() ) {
		int cur = Q.front();
		Q.pop();
		for(int dst = 0; dst < n; dst++ ) {
			if( D[dst] < 1 && a[cur][dst] == 1 ) {
				D[dst] = D[cur] + 1;
				Q.push(dst);
			}
		}
	}
	for (int i = 0; i < n;i++) {
	cerr << i+1 <<  " " << D[i] <<  endl;
	}
}

int main() {
	cin >> n;
	for ( int i = 0;i < n;i++) {
		D[i] = -1;
		for(int j= 0; j < n;j++) {
			a[i][j] = 0;
		}
	}
	for (int i = 0;i < n; i++){
		cin >> m;
		cin >> l;
		for(int j = 0; j < l;j++) {
			cin >> p;
			a[m-1][p-1] = 1;
		}
	}
	bfs(0);
}

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

using namespace std;

int D[100100] = {-1};//始点からの距離を入れる
int g[1001][1001]={{0}};//要素を0で初期化
void bfs(int src,int n){//srcは開始位置この場合だと頂点1だから0
  // 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(g[cur][dst]==1 && D[dst]==0){
        D[dst]=D[cur]+1;
        Q.push(dst);
      }
    }
  }
}
void ans(int n){
  for (int i = 0; i < n; ++i)
  {
    cout << i+1 <<" "<< D[i]<<endl;
  }

}

int main(){
  // int g[1001][1001]={{0}};//要素を0で初期化
  int n,a,b,c;
  cin >> n;
  for (int i = 0; i < n; ++i)
  {
    cin >> a >> b ;
    for (int i = 0; i < b; ++i)
    {
      cin >> c;
      g[a-1][c-1]=1;/* code */
    }
  }
  bfs(0,n);
  ans(n);
  // for (int i = 0; i < n; ++i)
  // {
  //    for (int j = 0; j < n; ++j)
  //    {
  //     if (j==n-1)
  //     {
  //       cout << g[i][j] << endl;
  //     }else{
  //       cout << g[i][j] <<" ";
  //     }
  //    }
  // }


}

C++: #include<iostream>
#include<queue>
using namespace std;
static const int N = 100;
static const int INFTY = (1 << 21);
int n, M[N][N];
int d[N];
void bfs(int s) {
	queue<int>q;
	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();
		for (int v = 0; v < n; v++) {
			if (M[u][v] == 0)continue;
			if (d[v] != INFTY)continue;
			d[v] = d[u] + 1;
			q.push(v);
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i + 1 << " " << ((d[i] == INFTY) ? (-1) : d[i]) << endl;
	}
}
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 <stdio.h>
#include <vector>
#define rep(i, n) for(int i = 0; i < n; ++i)
using namespace std;
 
int main(void) {
  int n, ans = 0, inf = 10000;
  scanf("%d", &n);
  int dis[n];
  rep(i, n) dis[i] = inf;
  dis[0] = 0;
  vector< int > vec[n];
  rep(i, n) {
    int u, k;
    scanf("%d%d", &u, &k);
    u--;
    rep(j, k) {
      int v;
      scanf("%d", &v);
      v--;
      vec[u].push_back(v);
    }
  }
  rep(i, n - 1) {
    rep(j, n) {
      vector< int >::iterator it;
      for(it = vec[j].begin(); it != vec[j].end(); ++it) {
        if(dis[*it] > dis[j] + 1) dis[*it] = dis[j] + 1;
      }
    }
    /*rep(j, n) printf("%d ", dis[j]);
    printf("\n");*/
  }
  rep(i, n) {
    if(dis[i] != inf) printf("%d %d\n", i + 1, dis[i]);
    else printf("%d -1\n", i + 1);
  }
  return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<cassert>
#include<cstdio>
#include<queue>

using namespace std;

int N, G[100][100], V[100], D[100];//G:２頂点,V:次数,D:距離

void bfs(int src){
	queue<int> Q;
	Q.push(src);
	fill(D, D + N, -1);
	D[src] = 0;
	while (!Q.empty()){
		int cur = Q.front();
		Q.pop();
		for (int k = 0; k < N; k++){
			if (G[cur][k] == 1 && D[k] == -1){
				D[k] = D[cur] + 1;
				Q.push(k);
			}
		}
	}
	for (int l = 0; l < N; l++){
		cerr << l + 1 << " " << D[l] << endl;
	}
}

int main(){
	scanf_s("%d", &N);
	int id, c;
	for (int i = 0; i < N; i++){
		scanf_s("%d", &id); id--;//配列は0から始まるので、頂点番号を-1して考える。
		scanf_s("%d", V + id);
		for (int j = 0; j < V[id]; j++){
			scanf_s("%d", &c); c--;//配列は0から始まるので、頂点番号を-1して考える。
			G[id][c] = 1;
		}
	}//データの読み込み完了。
	bfs(0);
}

C++: 
#include <iostream>
#include <stdio.h>
#include <queue>

using namespace std;

int** gmtrx;
int* v;
int total, n;

std::queue<int> que;

void operation(){
	int tmp = que.front();
	for(int i=0; i<n; ++i){
		if(gmtrx[tmp][i]){
			if(v[i]==-1){
				v[i]=v[tmp]+1;
				++total;
				que.push(i);
			}else{
				continue;
			}
		}
	}
	que.pop();
}

int main()
{
	scanf("%d",&n);

	gmtrx = new int*[n];
	v = new int [n]; //discovery

	for(int i=0; i<n; ++i){
		gmtrx[i] = new int[n];
		for(int j=0; j<n; ++j){
			gmtrx[i][j] = 0;
		}
		v[i] = -1;
	}

	for(int i=0; i<n; ++i){
		int v, num, a;
		scanf("%d %d",&v,&num);
		--v;
		for(int j=0; j<num; ++j){
			scanf("%d",&a);
			--a;
			gmtrx[v][a] = 1;
		}
	}

	que.push(0);
	v[0]=0;
	++total;
	while(que.size() && total!=n){
		operation();
	}

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

	for(int i=0; i<n; ++i){
		delete[] gmtrx[i];
	}
	delete[] gmtrx;
	delete[] v;

	return 0;
}