Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	nodes := make([]Node, n)

	for i := 0; i < n; i++ {
		nodes[i].list = make([]int, 0)
		nodes[i].d = -1
	}

	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		u--
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			v--
			nodes[u].list = append(nodes[u].list, v)
		}
	}

	queue := make([]int, n)
	queue[0] = 0
	nodes[0].d = 0
	d := 0
	i, j := 0, 1
	for i < j {
		d++
		prev := j
		for i < prev {
			for k, l := 0, len(nodes[queue[i]].list); k < l && i < n; k++ {
				if nodes[nodes[queue[i]].list[k]].d != -1 {
					continue
				}
				nodes[nodes[queue[i]].list[k]].d = d
				queue[j] = nodes[queue[i]].list[k]
				j++
			}
			i++
		}
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i+1, nodes[i].d))
	}

	writer.Flush()
}

// Node ...
type Node struct {
	list []int
	d    int
}

C++: #include<queue>
#include<iostream>
using namespace std;
int D[110];
int N,n,u,k,v;
int main()
{
    queue<int>Q;
    cin>>N;
    int A[N][N];
    for(int p=0;p<N;p++)
        for(int q=0;q<N;q++)
            A[p][q]=0;
    for(int p=0;p<N;p++)
        D[p]=2147483647;
    for(n=0;n<N;n++)
    {
        cin>>u>>k;
        for(int i=0;i<k;i++)
        {
            cin>>v;
            A[u-1][v-1]=1;
        }
    }
    Q.push(1);
    D[0]=0;
    while(!Q.empty())
    {
        int cur=Q.front();
        Q.pop();
            for(int j=0;j<N;j++)
            {
                if(A[cur-1][j]==1&&D[j]==2147483647)
                {
                    Q.push(j+1);
                    D[j]=D[cur-1]+1;
                }
            }
    }
    for(int i=0;i<N;i++)
    {
        if(D[i]==2147483647)
            D[i]=-1;
    }
    for(int i=0;i<N;i++)
    {
        cout<<(i+1)<<' '<<D[i]<<endl;
    }
    return 0;
}

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

struct edge{
    int node;
    edge *next;
}nodes[105];

int n,d[105],v[105];
queue<edge> E;

void bfs(){
    edge *e=E.front().next;
    while(e!=NULL){
        int num=e->node;
        if(v[num]==0){
            v[num]=1;
            d[num]=d[E.front().node]+1;
            E.push(nodes[num]);
        }
        e=e->next;
    }
    E.pop();
}

int main(){
    memset(v,0,sizeof(v));
    memset(d,-1,sizeof(d));
    cin>>n;
    int i,j;
    for(i=1;i<=n;i++){
        int ii,n_i;
        cin>>ii>>n_i;
        nodes[ii].node=ii;
        edge *first=&nodes[ii];
        for(j=0;j<n_i;j++){
            edge *e=new edge();
            cin>>e->node;
            first->next=e;
            first=e;
        }
    }
    d[1]=0;
    E.push(nodes[1]);
    while(E.size()!=0){
        bfs();
    }
    for(i=1;i<=n;i++)cout<<i<<" "<<d[i]<<endl;
    return 0;
}

C++: #include<iostream>
#include<queue>
#include<vector>
using namespace std;
vector<vector<int>> G(100);
vector<int> d(100);
const int INF = 1<<28;
void bfs(){
    queue<int> Q;
    Q.push(0);
    fill(d.begin(),d.end(),INF);
    d[0]=0;
    while(!Q.empty()){
        int u=Q.front();
        Q.pop();
        for(auto a:G[u]){
            if(d[a]!=INF) continue;
            d[a]=d[u]+1;
            Q.push(a);
        }
    }
}
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin>>n;
    for(int i=0;i<n;++i){
        int u,k;
        cin>>u>>k;
        for(int j=0;j<k;++j){
            int v;
            cin>>v;
            G[u-1].push_back(v-1);
        }
    }
    bfs();
    for(int i=0;i<n;++i)
        cout<<i+1<<' '<<d[i]<<endl;
}

C++: #include<iostream>
#include<queue>
#include<utility>
#define F first
#define S second
using namespace std;
typedef pair< int, int >p;//first = node , second = time

bool g[101][101];
int t[101];

main()
{
  int n, u, k, v;
  queue<p>que;

  cin >> n;

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

  que.push(p(0,0));
  t[0] = 0;
  while ( !que.empty() ) {
    p now = que.front(); que.pop();
    
    int pos = now.F;
    int time = now.S;
    
    for ( int i = 0; i < n ; ++i) {
      if ( g[pos][i] && t[i] == -1 ) {
	t[i] = time + 1;
	que.push(p(i,time+1));
      }
    }
  }

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

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

int main(){
  int n;
  vector<int> mat[100];
  cin >> n;
  for(int i=0;i<n;i++){
    int u,k;
    cin >> u >> k;
    for(int j=0;j<k;j++){
      int v;
      cin >> v;
      mat[i].push_back(v);
    }
  }

  int d[100];
  for(int i=0;i<n;i++) d[i]=(-1);

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

  while(!nb.empty()){
    for(vector<int>::iterator it=mat[nb.front()].begin();it!=mat[nb.front()].end();it++){
      if(d[*it]==-1){
        d[*it]=d[nb.front()]+1;
        nb.push(*it);
      }
    }
    nb.pop();
  }

  for(int i=1;i<=n;i++)
    cout << i << ' ' << d[i-1] << endl;
  
  return 0;
}

C++: /*
?????????: Graph I - Breadth First Search
URL: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_C
?????°
19:08 ??°?????????????????????????????£??¨??????????????????????????§???????????????????????£?????????
19:08 ???????????\????????\????????°??????????????????????¢????
19:09 ????????°???????????????????§£
19:13 ??¨???????????????????????£???
19:19 BFS????¨???¶???????¶??????????????????§??¨?????????????????????????????????
19:28 ???????????????????§?????????????????????£????????§????????????????????????????????????????????§????????????????????£????????????
*/
#include <iostream>
#include <vector>
#include <set>
#include <queue>
#define INF 114514
using namespace std;

int main()
{
	int n; cin>>n;
	vector< set<int> > graphdat(n+1);  
	for(int i=0;i<n;i++){
		int u; int k; cin >> u >> k;
		set<int> v;
		for(int j=0;j<k;j++){
			int tmp;
			cin >> tmp;
			v.insert(tmp);
		}
		graphdat[u] = v;
	}

	vector<int> distance(n+1);
	distance[1] = 0;
	for(int i=2;i<=n;i++){
		distance[i] = INF;
	}

	queue<int> Q;
	Q.push(1);

	while(!Q.empty()) {
		int cur = Q.front();
		Q.pop(); // pop?????????????????????????????¨?¬???\??§??????
		for(int dest=1; dest<=n; dest++) {
			if(graphdat[cur].find(dest) != graphdat[cur].end()) { // ??????????????????
				if(distance[dest] > distance[cur] + 1) { // ??´??°??§????????????
					distance[dest] = distance[cur] + 1;
					Q.push(dest);
				}
			}
		}
	}

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

}