Go: package main

import (
	"container/list"
	"fmt"
	"bufio"
	"os"
	"strconv"
)

const (
	N   = 100
	INF = 1 << 21
)

var (
	n        int
	adj      [N][N]int
	distance [N]int
)

func BFS(start int) {
	q := list.New()
	q.PushBack(start)
	for i := 0; i < n; i++ {
		distance[i] = INF
	}
	distance[start] = 0
	u := 0
	for q.Len() != 0 {
		u = q.Remove(q.Front()).(int)
		for v := 0; v < n; v++ {
			if adj[u][v] == 0 {
				continue
			}
			if distance[v] != INF {
				continue
			}
			distance[v] = distance[u] + 1
			q.PushBack(v)
		}
	}
	for i := 0; i < n; i++ {
		var d int
		if distance[i] == INF {
			d = -1
		} else {
			d = distance[i]
		}
		fmt.Printf("%d %d\n", i+1, d)
	}
}

func main() {
	var u, k, v int
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	scanner.Scan()
	n, _ = strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			adj[i][j] = 0
		}
	}
	for i := 0; i < n; i++ {
		scanner.Scan()
		u, _ = strconv.Atoi(scanner.Text())
		u -= 1
		scanner.Scan()
		k, _ = strconv.Atoi(scanner.Text())
		for j := 0; j < k; j++ {
			scanner.Scan()
			v, _ = strconv.Atoi(scanner.Text())
			v -= 1
			adj[u][v] = 1
		}
	}
	BFS(0)
}

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

int G[110][110];
int N,num,lines,tar;
int D[1000];
int ret[1000];

void bfs(int src);

int main() {
	for (int i=0;i<110;i++) {
		for(int j=0;j<110;j++) {
			G[i][j] = 0;
		}
	}
	for(int i=0;i<1000;i++) {
		D[i] = 100;
	}
	cin >> N;
	for(int i=0;i<N;i++) {
		cin >> num >> lines;
		for(int j=0;j<lines;j++) {
			cin >> tar;
			G[num][tar] = 1;
		}
	}
	/*
	for(int i=0;i<num+1;i++) {
		for(int j=0;j<num+1;j++) {
			cout << G[i][j] << " ";
		}
		cout << endl;
	}
	*/
	bfs(1);
	for(int i=1;i<num+1;i++) {
		if(ret[i] == 100) ret[i] = -1;
		cout << i << " " << ret[i] << endl;
	}

}
void bfs(int src) {
	int cur,dst;
	//cerr << "bfs root = " << src << endl;
	queue<int> Q; // ??´??°????????????????????\????????????
	Q.push(src);
	D[src] = 0; // ?????????
	while (! Q.empty()) {
		int cur = Q.front(); // ??????????´????????????????
		Q.pop();
// ???????¢??????¨??¨???
		ret[cur] = D[cur];
		//cerr << cur << " " << D[cur] << endl;
		for (int dst=1;dst<N+1;dst++) { // ???????????? dst ????????????
			if ((G[cur][dst] == 1) && (D[dst] == 100)) { // cur ?????? dst ??????????????????dst ???????¨??????????
				D[dst] = D[cur]+1; //
				Q.push(dst); // dst ????¨???????????????????
			}
		}
	}
}

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;
}