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 <list>
#include <cstdlib>
#include <climits>

const int MAX_N = 100;

struct Node {
  int v;
  int d;
  bool visited;
};

int main(void) {
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);  

  int n = 0;
  std::cin >> n;

  std::vector<std::vector<int> *> *graph = new std::vector<std::vector<int> *>(n + 1);
  std::vector<struct Node *> *nodes = new std::vector<struct Node *>(n + 1);
  
  for (int i = 1; i <= n; i++) {
    int v = 0;
    std::cin >> v;

    int k = 0;
    std::cin >> k;

    std::vector<int> *neighbors = new std::vector<int>(k);

    for (int j = 0; j < k; j++) {
      int a = 0;
      std::cin >> a;

      neighbors->at(j) = a;
    }

    graph->at(i) = neighbors;

    struct Node *node = (struct Node *) std::malloc(sizeof(struct Node));

    node->v = i;
    node->d = INT_MAX;
    node->visited = false;
    
    nodes->at(v) = node;
  }

  int count = 0;
  int start = 1;

  std::list<int> *stack = new std::list<int>();

  stack->push_back(nodes->at(start)->v);

  while (!stack->empty()) {
    std::vector<int> *newNodes = new std::vector<int>();

    while (!stack->empty()) {    
      int v = stack->front();
      stack->pop_front();

      if (count < nodes->at(v)->d) {
	nodes->at(v)->d = count;
      }
      
      nodes->at(v)->visited = true;
      
      std::vector<int> *neighbors = graph->at(v);

      for (std::vector<int>::iterator iterator = neighbors->begin(); iterator != neighbors->end(); ++iterator) {
	struct Node *node = nodes->at(*iterator);

	if (!node->visited) {
	  newNodes->push_back(node->v);
	}
      }
    }

    for (std::vector<int>::iterator iterator = newNodes->begin(); iterator != newNodes->end(); ++iterator) {
      stack->push_front(*iterator);
    }

    count++;
  }

  for (std::vector<struct Node *>::iterator iterator = nodes->begin() + 1; iterator != nodes->end(); ++iterator) {
    struct Node *node = *iterator;

    if (node->d == INT_MAX) {
      node->d = -1;
    }
        
    std::cout << node->v << " " << node->d << std::endl;
  }
  
  return 0;
}

C++: #include <bits/stdc++.h>
#define ll long long
#define INF 999999999
#define MOD 1000000007

using namespace std;

typedef pair<int,int>P;

const int MAX_N = 100;

vector<int> G[MAX_N];
int d[MAX_N];

int main()
{
	int n;
	cin >> n;
	for(int i=0;i<n;i++){
		int id;
		cin >> id;
		int k;
		cin >> k;
		for(int j=0;j<k;j++){
			int to;
			cin >> to;
			G[id-1].push_back(to-1);
		}
	}
	fill(d,d+n,INF);
	deque<int> bfs;
	bfs.push_back(0);
	d[0] = 0;
	while(!bfs.empty()){
		int v = bfs.front();
		bfs.pop_front();
		for(int i=0;i<G[v].size();i++){
			int to = G[v][i];
			if(d[to] > d[v]+1){
				d[to] = d[v]+1;
				bfs.push_back(to);
			}
		}	
	}
	for(int i=0;i<n;i++){
		if(d[i] == INF){
			d[i] = -1;
		}
		cout << i+1 << " " << d[i] << "\n";
	}
}

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 <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];//通?距?管理??状?(color)
void bfs(int s){
    queue<int> q;//使用?准?中的queue
    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;
}