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>
#define rep(i, n) for(int i = 0; i < n; i++)
using namespace std;
using Graph = vector<vector<int>>;

int main(){
  int n;
  cin >> n;
  Graph G(n);
  rep(i, n){
    int u, k;
    cin >> u >> k;
    u--;
    rep(j, k){
      int v;
      cin >> v;
      v--;
      G[u].push_back(v);
    }
  }
  
  vector<int> d(n, -1);
  queue<int> que;
  
  d[0] = 0;
  que.push(0);
  
  while(!que.empty()){
    int v = que.front();
    que.pop();
    for(int nv : G[v]){
      if (d[nv] != -1) continue;
      
      d[nv] = d[v] + 1;
      que.push(nv);
    }
  }
  
  rep(i, n) cout << i + 1 << ' ' << 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], d[N];

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()) {
		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;
    }

}

int main() {
	int v, k ,u;
	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;
		for(int j = 0; j < k; j++) {
			cin >> v;
			M[u-1][v-1] = 1;
		}
	}
	
	bfs(0);
	
	return 0;
	
}

C++: #include<bits/stdc++.h>
using namespace std;
int n;
int a[101][101];
int d[101];

void bfs(int s){
	queue<int>q;
	q.push(s);
	memset(d,-1,sizeof(d));
	d[s]=0;
	int u;
	while(!q.empty()){
		u=q.front();
		q.pop();
		for(int v=0;v<n;v++){
			if(a[u][v]==0)continue;
			if(d[v]!=-1)continue;
			d[v]=d[u]+1;
			q.push(v);
		}
	} 
	for(int i=0;i<n;i++){
		cout<<i+1<<" "<<d[i]<<endl;
	}
}

int main(){
	cin>>n;
	memset(a,0,sizeof(a));
	int u,k,v;
	for(int i=0;i<n;i++){
		cin>>u>>k;
		u--;
		for(int j=0;j<k;j++){
			cin>>v;
			v--;
			a[u][v]=1;
		}
	}
	bfs(0);
}

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

int main(){
  queue<int> q;
  int n,k,u,max=0;
  int g[101]={},c[101];
  int d[101][101]={};
  int di;
  cin>>n;
  for(int i=0;i<101;i++) c[i]=-1;
  c[1]=0;
  g[1]=1;
  for(int i=0;i<n;i++){
    cin>>u>>k;
    if(max<k) max=k;
    for(int j=0;j<k;j++){
      cin>>di;
	d[u][j]=di;
    }
  }

  q.push(1);

  int a;
  while(!q.empty()){
 a=q.front();
    for(int i=0;i<=max;i++){

      if( d[a][i]>1 && g[d[a][i]]==0){
	g[d[a][i]]=1;
	q.push(d[a][i]);
	 c[d[a][i]]=c[a]+1;
      }
    }
      q.pop();
  }
  for(int i=1;i<=n;i++) cout<<i<<" "<<c[i]<<endl;
  return 0;
}

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

#define _GLIBCXX_DEBUG
#define all(v) (v).begin(),(v).end()

using namespace std;

using ll=long long;
using pii=pair<int, int>;
using vi=vector<int>;

const ll INF=1LL<<60;
const int MOD=1e9+7;

int main(){
    int n; cin >> n;
    vector<vi> G(n, vi(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);
        }
    }
    queue<int> que;
    que.push(0);
    vi dist(n, -1);
    dist[0]=0;
    while(!que.empty()){
        int v=que.front();
        que.pop();
        for(auto &nv: G[v]){
            if(dist[nv] != -1) continue;
            dist[nv]=dist[v]+1;
            que.push(nv);
        }
    }
    for(int i=0; i<n; i++){
        cout << i+1 << " " << dist[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 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;
	}
}

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;
}

C++: #include <bits/stdc++.h>
using namespace std;

int main()
{

	int n;
	cin >> n;
	vector<vector<int>> g(n+1);

	for (int i=1;i<=n;++i)
	{
		int u,k;
		cin >> u >> k;
		for (int j=0;j<k;++j)
		{
			int v;
			cin >> v;
			g[u].push_back(v);
		}
	}

	vector<int> dist(n+1);
	for (int i=1;i<=n;++i)
	{
		dist[i]=-1;
	}
	queue<int> q;

	q.push(1);
	dist[1]=0;
	while (q.empty()==false)
	{
		int node=q.front();
		q.pop();

		for (int i=0;i<g[node].size();++i)
		{
			int nn=g[node][i];
			if (dist[nn]<0)
			{
				dist[nn]=dist[node]+1;
				q.push(nn);
			}
		}
	}

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