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 <cstdio>
#include <iostream>
#include <queue>
using namespace std;

static const int MAX_NUM = 101;
static const int NO_VISIT  = 0;
static const int END_VISIT = 2;

void BFS(int *matrix, int num)
{
    int i;
    int state[MAX_NUM]    = {0};
    int distance[MAX_NUM];
    queue<int> Q;
    int target;
    int dist = 0;
    int *tmp;
    bool first;

    for (i = 1; i <= num; i++) {
        distance[i] = -1;
    }

    Q.push(1);
    state[1] = END_VISIT;
    distance[1] = 0;

    while (Q.empty() == false) {
        target = Q.front();
        Q.pop();
        tmp = matrix + target * MAX_NUM;
        first = true;
        for (i = 1; i <= num; i++) {
            if ((*(tmp + i) == 1) && (state[i] == NO_VISIT)) {
                distance[i] = distance[target] + 1;
                Q.push(i);
                state[i] = END_VISIT;
            }
        }
    }

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

    return;
}

int main(void)
{
    int i, j;
    int num;
    int elem;
    int nume;
    int tmp;
    int matrix[MAX_NUM][MAX_NUM];

    scanf("%d", &num);
    for (i = 0; i < num; i++) {
        scanf("%d %d", &elem, &nume);
        for (j = 0; j < nume; j++) {
            scanf("%d", &tmp);
            matrix[elem][tmp] = 1;
        }
    }

    BFS(&matrix[0][0], num);

    return 0;
}

C++: #include <iostream>
#include <cstring>
#include <algorithm>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
using namespace std;

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

int n, M[N][N];
int d[N]; //距離で訪問状態を管理する

void bfs(int s) {
    queue<int> q;
    q.push(s);

    for(int i = 0; i < n; i++)
        d[i] = INF;

    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] != INF) continue;
            d[v] = d[u] + 1;
            q.push(v);
        }
    }
    for(int i = 0; i < n; i++) {
        cout << i+1 << " "  << ( (d[i] == INF) ? (-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<iostream>
#include<queue>

using namespace std;

static const int N=100;
static const int INF=(1<<21);
int n, MA[N][N];
int d[N];

void Bfs(int s){
  queue<int> q;
  q.push(s);

  for(int i=0; i<n; i++)
  d[i]=INF;

  d[s]=0;
  int u;

  while(!q.empty())
  {
    u=q.front();
    q.pop();

    for(int v=0; v<n; v++)
    {
      if(MA[u][v]==0)
        continue;
      if(d[v] != INF)
        continue;
      d[v]=d[u]+1;
      q.push(v);
    }
  }
  for(int i=0; i<n; i++)
  {
    cout << i+1 << " " <<((d[i] == INF) ? (-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++)
      MA[i][j]=0;
  }

  for(int i=0; i<n; i++)
  {
    cin >> u >> k;
    u--;
    for(int j=0; j<k; j++)
    {
      cin >> v;
      v--;
      MA[u][v]=1;
    }
  }

  Bfs(0);

  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n)   for(int i=0;i<(n);++i)
#define SORT(c)    sort((c).begin(),(c).end())
#define CLR(a)     memset((&a), 0 ,sizeof(a))//clear memory
#define dump(x)    cerr << #x << " = " << (x) << endl;//debug
#define debug(x)   cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
#define EPS        1e-10//sample:if((double)>=(double)+EPS)
//cin,cout release
//std::cin.tie(0);
//ios::sync_with_stdio(false);

using namespace std;

int n,v[100+1][100+1]={},d[1000]={},color[1000]={};
int q[1000]={},head=0,tail=0;
void bfs(int s){
  rep(i,n){
    if(v[s][i]==0&&s!=i){
      color[s]=0;
      d[i]=INT_MAX;
    }
  }
  color[s]=1;
  d[s]=0;
  head=tail=0;
  q[tail++]=s;
  while(head!=tail){
    int u=q[head++];
    rep(i,n){
      if(v[u][i]==0)continue;
      if(color[i]==0){
	color[i]=1;
	d[i]=d[u]+1;
	q[tail++]=i;
      }
    }
    color[u]=2;
  }
}
int main(){
  cin>>n;
  int u,k,in;
  rep(i,n){
    cin>>u>>k;
    rep(j,k){
      cin>>in;
      v[u-1][in-1]=1;
    }
  }
  //rep(i,n)
  bfs(0);
  rep(i,n){
    cout<<i+1<<" ";
    if(d[i]==INT_MAX)cout<<-1;
    else cout<<d[i];
    cout<<endl;
  }
  return 0;
}