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++: 
#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++: #include <stdio.h>
#include <stdlib.h>

#define WHITE 0
#define GRAY 1
#define BLACK 2
#define MAX_N 110

int n,time,head,tail;
int queue[MAX_N];
int *dist;
int *color;
int **matrix;

void enqueue(int);
int dequeue(void);
void bfs(void);

int main(){
  int i,j,u,k,v;

  scanf("%d",&n);

  //queue = malloc(n * sizeof(int));
  color = malloc(n * sizeof(int));
  dist = malloc(n * sizeof(int));

  matrix = malloc(n * sizeof(int *));
  for(i = 0 ; i < n ; i++){
    matrix[i] = malloc(n * sizeof(int));
 }
 for(i = 0 ; i < n ; i++){
   dist[i] = -1;
 }
 for(i = 0 ; i < n ; i++){
   for(j = 0 ; j < n ; j++){
     matrix[i][j] = 0;
   }
 }

 for(i = 0 ; i < n ; i++){
    scanf("%d",&u); u--;
    scanf("%d",&k);
    for(j = 0 ; j < k ; j++){
      scanf("%d",&v); v--;
      matrix[u][v] = 1;
    }
  }

  bfs();
  for(i = 0 ; i < n ; i++){
    printf("%d %d\n",i+1,dist[i]);
  }

  for(i = 0 ; i < n ; i++){
    free(matrix[i]);
  }
  free(matrix);
  //free(queue);
  free(dist);
  free(color);
  return 0;
}

void bfs(){
  int u,i;

  head = tail = 0;
  color[0] = GRAY;
  dist[0] = 0;
  enqueue(0);

  while(head != tail){
    u = dequeue();
    for(i = 0 ; i < n ; i++){
      if(matrix[u][i] == 1 && color[i] == WHITE){
        color[i] = GRAY;
        dist[i] = dist[u] + 1;
        enqueue(i);
      }
    }
    color[u] = BLACK;
  }
}

void enqueue(int q){
  queue[tail%MAX_N] = q;
  tail++;
}

int dequeue(){
  int v = queue[head%MAX_N];
  head++;
  return v;
}

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

using namespace std;

	int TIME = 0;
	int d[101];
	int num;
	int graph[101][101] = {0};

int main(){
	int hon;
	int eda;
	int ver;
	queue<int> QUE;

	cin>>num;

	for(int i=1;i<=num;i++)
		d[i] = -1;

	for(int i=0;i<num;i++){
		cin>>eda;
		cin>>hon;
		for(int j=0;j<hon;j++){
			cin>>ver;
			graph[eda][ver]++;
		}
	}
	QUE.push(1); //start
	d[1] = 0;

	do{
		ver = QUE.front();
		QUE.pop();
		for(int i=1;i<=num;i++){
			if(graph[ver][i] == 1 && d[i]==-1){
				d[i] = d[ver] + 1;
				QUE.push(i);
			}
		}
	}while(!QUE.empty());
		
	for(int i=1;i<=num;i++){
		cout<<i<<" "<<d[i]<<endl;
	}

	return 0;
}

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);

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;

}

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;
  }
}

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

using namespace std; 

int main(void) {
	int nov,noe,u,v;
	cin >> nov;
	vector< vector<int> > adj(nov);
	for (int i = 0; i < nov; ++i) {
		cin >> u;
		cin >> noe;
		adj[u-1] = vector<int>(noe);
		for (int j = 0; j < noe; ++j) {
			cin >> adj[u-1][j];
			--adj[u-1][j];
		}
	}
	vector<int> res(nov,-1);
	res[0] = 0;
	queue< pair<int,int> > q;
	q.push({0,0});
	pair<int,int> now;
	while (!q.empty()) {
		now = q.front();
		q.pop();
		for (int i = 0; i < adj[now.first].size(); ++i) {
			if (res[adj[now.first][i]] < 0) {
				res[adj[now.first][i]] = now.second+1;
				q.push({adj[now.first][i],now.second+1});
			}
		}
	}
	for (int i = 0; i < nov; ++i) {
		cout << i+1 << " ";
		cout << res[i] << endl;
	}
	return 0;
}

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

int main(){
	int n,m,l,i,j,p;
	int f[1000][1000];
	int D[1000] = {};
	cin >> n;
	for(i = 0; i < n; i++){
		cin >> m;
		cin >> p;
		for(j = 0; j < p; j++){
			cin >> l;
			f[m][l] = 1;
		}
	}
	queue<int> Q;
	Q.push(1);
	while(!Q.empty()){
		int c = Q.front();
		Q.pop();
		for(i = 2; i <= n; i++){
			if(f[c][i] == 1 && D[i] == 0){
				D[i] = D[c] + 1;
				Q.push(i);
			}
		}
	}				
	for(i = 1; i <= n; i++){
		if (D[i] == 0 && i !=1)
			D[i] = -1;
		cout << i << " " << D[i] << endl;
	}
}