Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	visitedAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		visitedAt: -1,
		adjs: adjs,
	}
}

func (v *vertex) isVisited() bool {
	return v.visitedAt >= 0
}

func bfs(id vertexId, vqueue []vertexId, vertices []vertex) {
	vertex := &vertices[id-1]
	for _, vid := range vertex.adjs {
		if !vertices[vid-1].isVisited() {
			(&vertices[vid-1]).visitedAt = vertex.visitedAt+1
			vqueue = append(vqueue, vid)
		}
	}
	if len(vqueue) > 0 {
		nextId := vqueue[0]
		nextVqueue := vqueue[1:]
		bfs(nextId, nextVqueue, vertices)
	}
}

func solveBfs(vertices []vertex) {
	vertex := &vertices[0]
	vertex.visitedAt = 0
	vqueue := make([]vertexId, 0)
	bfs(vertex.id, vqueue, vertices)
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	solveBfs(vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d\n", vertices[i].id, vertices[i].visitedAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func nextInt(sc *bufio.Scanner) (int, error) {
	return strconv.Atoi(nextText(sc))
}

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

typedef struct{
  int A[1000];
  int ans;
  bool c;
}node;
node T[1000];
int Q[10000000];
int head=0;
int tail=1;
int n;

void function(int num){
  while(true){
    if(head==tail)break;
    num=Q[head++];
    for(int i=2;i<=n;i++){
      if(T[num].A[i]==1){
	if(T[i].ans==0){
	  T[i].ans=T[num].ans+1;
	  T[num].A[i]=0;
	}
	Q[tail++]=i;
      }
    }
    //    cout<<"Q "<<Q[head]<<endl;
    //  cout<<head<<" "<<tail<<endl;
  }

}

int main(){
  int num;
  int son;
  int z;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>num;
    cin>>son;
    for(int j=0;j<son;j++){
      cin>>z;
      T[num].A[z]=1;
      }
  }
  Q[0]=1;
  function(1);
  T[1].ans=0;
  for(int i=2;i<=n;i++){
    if(T[i].ans==0){
      T[i].ans=-1;
    }
  }

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


  return 0;
}

C++: #include<bits/stdc++.h>

struct node{
    int d, flag;
    node(){
        d = 0;
        flag = 0;
    }
};

int main(void){
    int n;
    int ind, num, a;
    int time, ndi;

    std::cin >> n;
    std::vector<node> nd(n);
    std::vector<std::vector<int>> b(n, std::vector<int>(n));
    std::queue<int> st;

    for(int i = 0; i < n; i++){
        std::cin >> ind >> num;
        ind--;
        for(int i = 0; i < num; i++){
            std::cin >> a;
            a--;
            b[ind][a] = 1;
        }
    }

    time = 0;
    int x = 0;
    //for(int x = 0; x < n; x++){
        if(nd[x].flag == 0){
            ndi = x;
            time++;
            nd[x].flag = 1;
        
            st.push(x);
        }
    
        

        while(st.empty() != 1){
            //std::cout << ndi+1 << " " << time << std::endl;
            //time++;
            int tmp = -1;
            int tmp2;
            for(int i = 0; i < n; i++){
                if(b[ndi][i] == 1 && nd[i].flag == 0){
                    tmp = i;
                    tmp2 = x;
                    break;
                }
            }
            if(tmp == -1){
                //std::cout << ndi+1 << " " << time << std::endl;

                nd[ndi].flag = 1;
                st.pop();
                if(st.empty() != 1){
                    ndi = st.front();
                }

                continue;
            }

            nd[tmp].flag = 1;
            nd[tmp].d = nd[ndi].d + 1;
            st.push(tmp);
            
        }
    //}
    for(int i = 0; i < n; i++){
        if(nd[i].flag == 0 && i != 0){
            nd[i].d = -1;
        }
    }
    for(int i = 0; i < n; i++){
        std::cout << i+1 << " " << nd[i].d << std::endl;
    }

    return 0;
}

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

using namespace std;

int color[100];
int d[100];
int f[100];
int G[100][100];
int nt[100];
int n;

int WHITE = 1;
int GRAY = 2;
int BLACK = 3;

int _time = 0;

int next(int u) {
  for (int v = nt[u]; v < n; v++) {
    nt[u] = v + 1;
    if (G[u][v]) return v;
  }

  return -1;
}

void dfs(int r) {
  for (int i = 0; i < n; i++) nt[i] = 0;

  queue<int> S;

  S.push(r);
  color[r] = GRAY;

  while(!S.empty()){
    int u = S.front();

    while(1) {
      int v = next(u);

      if(v != -1) {
        if(color[v] == WHITE) {
          color[v] = GRAY;

          S.push(v);

          d[v] = d[u] + 1;
        }
      } else {
        break;
      }
    }

    S.pop();
  }
}

void dfs_init() {
  for(int i = 0; i < n; i++) {
    color[i] = WHITE;
  }

  dfs(0);

  for(int i = 0; i < n; i++) {
    if(color[i] == WHITE) {
      d[i] = -1;
    }
  }
}

int main() {
  int m, k, l;
  cin >> n;

  for (int i = 0; i < n; i++) {
    cin >> k;
    cin >> m;

    for (int j = 0; j < m; j++) {
      int l;
      cin >> l;

      G[k-1][l-1] = 1;
    }
  }

  for (int i = 0; i < n; i++) {
    dfs_init();
  }

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

C++: #include<bits/stdc++.h>
#define INF 0x3f3f3f3f
#define rep(i,n)for(int i=0;i<n;i++)
using namespace std;
typedef pair<int,int>P;

vector<int>E[100];
int d[100];
int main(){
	int n;cin>>n;
	rep(i,n){
		int u,k;cin>>u>>k;u--;
		rep(i,k){
			int v;cin>>v;v--;
			E[u].push_back(v);
		}
	}
	memset(d,0x3f,sizeof(d));
	queue<P>que;
	d[0]=0;que.push(P(0,0));
	while(!que.empty()){
		P p=que.front();que.pop();
		for(int u:E[p.second]){
			if(d[u]>p.first+1){
				d[u]=p.first+1;
				que.push(P(d[u],u));
			}
		}
	}
	rep(i,n){
		if(d[i]==INF)cout<<i+1<<" -1"<<endl;
		else cout<<i+1<<' '<<d[i]<<endl;
	}
}