Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

func stringifyArray(arr []int) string {
	return strings.TrimRight(fmt.Sprintf("%+v", arr)[1:], "]")
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, &g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

func fillDistancesByBreadthFirstSearch(g *DirectedGraph, startNode *DirectedGraphNode) {
	startNode.visited = true
	startNode.d = 0

	queue := Queue{}
	queue.enqueue(startNode)
	for !queue.isEmpty() {
		u := queue.dequeue().node
		for _, adjacent := range u.adjacents {
			if !adjacent.visited {
				adjacent.visited = true
				adjacent.d = u.d + 1
				adjacent.parent = u
				queue.enqueue(adjacent)
			}
		}
		u.visited = true
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	// fmt.Println(g)
	fillDistancesByBreadthFirstSearch(g, &g.nodes[1])
	// fmt.Println(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		distance := node.d
		if distance == infty {
			distance = -1
		}
		fmt.Println(node.key, distance)
	}
}

C++: import java.util.LinkedList;
import java.util.Scanner;



public class Main {
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int size = sc.nextInt();
		AdjListGraph g = new AdjListGraph(size, true);
		for (int i = 0; i < size; i++){
			int v = sc.nextInt()-1;
			int d = sc.nextInt();
			for(int j=0; j<d; j++){
				g.addEdge(v, sc.nextInt()-1);
			}
		}
		g.BFS(0);
	}

}


class Pair{
	int key;int value;
	Pair(int K, int V){key = K; value = V;}
	int getKey(){return key;}
	int getValue(){return value;}
}	

class AdjListGraph { // http://theoryofprogramming.com/adjacency-list-in-java/
	private boolean digraph;
	private final LinkedList<Pair>[] adjList;
	@SuppressWarnings("unchecked")
	AdjListGraph(int numV, boolean flag){
		adjList = (LinkedList<Pair>[]) new LinkedList[numV];
		for (int i = 0; i < adjList.length; i++) {
			adjList[i] = new LinkedList<>();
		}
		digraph = flag;
	}
	boolean directed(){return digraph;} //return the graph is directed or not
	int getNumOfVertices(){return adjList.length;} //return the num of vertices
	public void addEdge(int startV, int endV, int weight) {
		adjList[startV].add(new Pair(endV, weight));
		if(!digraph){adjList[endV].add(new Pair(startV, weight));}
	} //add an edge to the graph. 
	public void addEdge(int startV, int endV) {
		addEdge(startV, endV, 1); 
	} //weight is set to 1 as a default
	public LinkedList<Integer> getEdgesFromVertexNoWeight(int startV) {
		LinkedList< Integer > edgeList= (LinkedList< Integer >) new LinkedList<Integer>();
		for(Pair pair : adjList[startV]){
			edgeList.add(pair.getKey());
		}
		return edgeList;
	} // get the list of the edges leaving startV. This is for no weight graph. 
	public void print() {
		int i = 0;
		for (LinkedList<Pair> list : adjList) {
			System.out.print("adjList[" + i + "] -> ");
			for (Pair edge : list) {System.out.print(edge.getKey() + "(" + edge.getValue() + ")");}
			i++;
			System.out.println();
		}
	}
	void BFS(int src){
		boolean visited[] = new boolean[getNumOfVertices()];		
		int dist[] = new int[getNumOfVertices()];
		LinkedList<Integer> queue = new LinkedList<Integer>();
		visited[src]=true;	
		queue.add(src);	
		while (queue.size() != 0){
			int tmp = queue.poll();
			LinkedList<Integer> neighbors =  getEdgesFromVertexNoWeight(tmp);
			for(Integer i : neighbors){
				if(!visited[i]){
					visited[i] = true;
					dist[i] = dist[tmp]+1;
					queue.add(i);
				}
			}
		}
		for(int i=0; i< dist.length ; i++){
			if(i!=src && dist[i]==0){
				dist[i]=-1;
			}
		}
		for(int i=0; i< dist.length ; i++){
			System.out.println(Integer.toString(i+1) + " " +  dist[i]);
		}
//		System.out.println(Arrays.toString(dist));
	}
}

C++: #include <iostream>
#define INF (1<<25)
#define MAX 1001
using namespace std;

template <typename T>
class queue{
  private:
    T array[MAX];
    int head, tail, n;
  public:
    queue(int n){
      head=tail=0;
      this->n = n;
    }

    void push(T value){
      if (head == (tail+1)%n)
        return ;
      array[tail] = value;
      tail = (tail+1)%n;
    }

    bool empty(){
      if (head == tail)
        return true;
      return false;
    }

    void pop(void){
      if (head == tail) return;
      head = (head+1)%n;
    }

    T front(void){
      return array[head];
    }
};
int graph[MAX][MAX];
bool isDiscoverd[100];
int dist[100];
int dim[MAX];

void bfs(int i){
  queue<int> searchQueue(MAX);
  searchQueue.push(i);
  while(!searchQueue.empty()){
    auto current = searchQueue.front();
    int k = dim[current];
    searchQueue.pop();
    isDiscoverd[current] = true;
    for (auto ite=graph[current] ; ite != graph[current]+k ; ++ite){
      dist[*ite] = min(dist[*ite], dist[current]+1);
      if (!isDiscoverd[*ite]) searchQueue.push(*ite);
    }
  }
}

int main(){
  int n;
  cin >> n;
  for (int i=0;i<n;++i){
    int id;
    cin >> id;
    cin >> dim[id];
    for(int j=0;j<dim[id];++j){
      int temp;
      cin >> temp;
      graph[id][j] = temp;
      isDiscoverd[id]=false;
    }
  }

  dist[1] = 0;
  for (int i=2;i<=n;++i)
    dist[i] = INF;

  bfs(1);

  for (int i=1;i<=n;i++){
    cout << i << " " << (dist[i]>=INF?-1:dist[i]) <<endl;
  }

  return 0;
}

C++: 
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <ctime>
#include <string>
#include <queue>

using namespace std;

const int MAX_N = 100;
int n;
int suji[MAX_N];
int	num[MAX_N];
int adj[MAX_N][MAX_N];
int ans[MAX_N][MAX_N];
int D[MAX_N];

void bfs(int src){
	queue<int> Q;
	Q.push(src);
	D[src] = 0;

	while(!Q.empty()){
		int cur = Q.front();
		Q.pop();

		for(int i = 1; i < n; i++){
			if(ans[cur][i] == 1 && D[i] == 0){
				D[i] = D[cur] + 1;
				Q.push(i);
			}
		}
	}
}


int main(void){

	cin >> n;
	for(int i = 0; i < n; i++){
		
		cin >> suji[i] >> num[i];

		
		for(int j = 0; j < num[i]; j++){
			cin >> adj[i][j];
			adj[i][j] -= 1;
		}
	}

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

	for(int i = 0; i < n; i++){
		for(int j = 0; j < num[i]; j++){
			ans[i][adj[i][j]] = 1;
		}
	}

	bfs(0);

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