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 <bits/stdc++.h>
using namespace std;
#define REP(i, s, n) for (int i = s; i < n; ++i)
#define rep(i, n) REP(i, 0, n)
#define SORT(c) sort((c).begin(), (c).end())
#define IINF INT_MAX
#define LLINF LLONG_MAX
#define DEBUG true
// sort(a.begin(), a.end(), std::greater<int>());

/*
std::vector<std::string> split(const std::string &input, char delimiter)
{
    std::istringstream stream(input);

    std::string field;
    std::vector<std::string> result;
    while (std::getline(stream, field, delimiter))
    {
        result.push_back(field);
    }
    return result;
}
*/
vector<int> data[100];
int finds[100];
/*
int dfs(int foo, int timer)
{
    //foo is node number
    if (finds[foo].first != -1)
        return timer;
    finds[foo].first = ++timer;
    int result = timer;
    if (data[foo].size() != 0)
    {
        rep(i, data[foo].size())
        {
            result = dfs(data[foo][i], result);
        }
    }
    finds[foo].second = ++result;
    return result;
}
*/
int main()
{
    int n;
    cin >> n;
    rep(i, n)
    {
        int temp;
        cin >> temp;
        cin >> temp;
        rep(j, temp)
        {
            int hoge;
            cin >> hoge;
            data[i].push_back(hoge - 1);
        }
        finds[i] = -1;
    }
    queue<int> que;
    que.push(0);
    finds[0] = 0;
    while (!que.empty())
    {
        int temp = que.front();
        que.pop();
        rep(i, data[temp].size())
        {
            if (finds[data[temp][i]] == -1)
            {
                finds[data[temp][i]] = finds[temp] + 1;
                que.push(data[temp][i]);
            }
        }
    }
    rep(i, n)
    {
        cout << i + 1 << " " << finds[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() {

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

  int u, k, v;
  for (int i = 0; i < n; i++) {
    cin >> u >> k;
    u--; // to 0 origin
    for (int j = 0; j < n; j++) {
      cin >> v;
      v--; // to 0 origin
      M[u][v] = 1;
    }
  }

  bfs(0);

  return 0;
}

C++: #include <bits/stdc++.h>
#include <bits/stdc++.h>
#define r(i,a,n) for(int i=a;i<n;i++)
using namespace std;
int a[101][101],start[101],end[101],n,p=0,v[101];
queue<int> q;
void bfs(int u){
	q.push(u);
	v[u]++;
	while(!q.empty()){
		u=q.front();q.pop();
		r(i,1,n+1)if(!v[i]&&a[u][i]){
			v[i]++;
			q.push(i);
			start[i]=start[u]+1;
		}
	}
}
int main(){
	int q,qq,qqq;
	cin>>n;
	r(i,0,n){
		cin>>q>>qq;
		r(i,0,qq){
			cin>>qqq;
			a[q][qqq]++;
		}
	}
	//r(i,1,n+1)if(!v[i])
	bfs(i);
	r(i,1,n+1)cout<<i<<' '<<start[i]<<endl;
}

C++: #include <algorithm>
#include <iostream>
#include <queue>
#include <string>
using namespace std;
static const int MAX = 100;
int N;
int ADJ[MAX][MAX];
int depth[MAX];

enum STATUS { ACTIVE = 0, MARKED, VISITED, };
int status[MAX] = {ACTIVE};

void visit(int id) {
  status[id] = VISITED;
}
void mark(int id) {
  status[id] = MARKED;
}

void bfs(int id) {
  queue<int> q;
  q.push(id);
  depth[id] = 0;

  while (!q.empty()) {
    int u = q.front();
    q.pop();
    visit(u);
    for (int i = 0; i < N; i++) { 
      if (ADJ[u][i] && status[i] == ACTIVE) {
        q.push(i);
        mark(i);
        depth[i] = depth[u] + 1;
      }
    }
  }
}

int main() {
  cin >> N;
  int id, nn, x;
  for (int i = 0; i < N; i++) {
    cin >> id >> nn;
    id--; // 0-based
    for (int j = 0; j < nn; j++) {
      cin >> x;
      x--; // 0-based
      ADJ[id][x] = 1;
    }
  }
  for (int i = 0; i < N; i++)
    depth[i] = -1;

  bfs(0);
  for (int i = 0; i < N; i++)
    cout << i+1 << " " << depth[i] << endl;
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<cassert>
#include<cstdio>
#include<queue>
 
using namespace std;
 
int N, G[100][100], V[100], D[100];//G:２頂点,V:次数,D:距離
 
void bfs(int src){
    queue<int> Q;
    Q.push(src);
    fill(D, D + N, -1);
    D[src] = 0;
    while (! Q.empty()){
        int cur = Q.front();
        Q.pop();
        cerr << cur+1 << " " << D[cur] << endl;
        for (int k = 0; k < N; k++){
            if (G[cur][k] == 1 && D[k] == -1){
                D[k] = D[cur]+1;
                Q.push(k);
            }
        }
    }
}
 
int main(){
    scanf("%d", &N);
        int id, c;
        for (int i = 0; i < N; i++){
            scanf("%d", &id); id--;//配列は0から始まるので、頂点番号を-1して考える。
            scanf("%d", V + id);
            for (int j = 0; j < V[id]; j++){
                scanf("%d", &c); c--;//配列は0から始まるので、頂点番号を-1して考える。
                G[id][c] = 1;
            }
        }//データの読み込み完了。
    bfs(0);
   return 0;
}