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<stdio.h>
#include<limits.h>
#define MAX 101
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define TRUE 1
#define FALSE 0
/*void DFSVisit(int);
  void DFS(void);*/
void BFS(int);
int deQueue(void);
void enQueue(int);
int isEmpty(void);
int G[MAX][MAX];
int D[MAX];
int F[MAX];
int color[MAX];
int Q[MAX];
int n;
int time;
int head = 0, tail = 0;
main(){
  int i, j, m, k, value, start = 1;
  scanf("%d",&n);

  for(i = 1; i <= n; i++){
    for(j = 1; j <= n; j++){

      G[i][j] = 0;

    }
  }

  for(i = 1; i <= n; i++){

    scanf("%d %d", &k, &m);

    for(j = 1; j <= m; j++){

      scanf("%d",&value);

      G[i][value] = 1;
    }
  }
 
  BFS(start);

  for(i = 1; i <= n; i++)
    {
      if(D[i]==INT_MAX)D[i] = -1;
      printf("%d %d\n", i, D[i]);
    }

 return 0;

}




/*void DFS(void){
  int u;

  for( u = 1; u <= n; u++ ){

    color[u] = WHITE;

  }

  time = 0;

 for( u = 1; u <= n; u++ ){
   if( color[u] == WHITE )
     DFSVisit(u);

  }

}

void DFSVisit(int u){
  int v;

  color[u] = GRAY;

  time++;
 
  D[u] = time;

  for(v = 1; v <= n ; v++){

    if(G[u][v] == 1 && color[v] == WHITE)
      DFSVisit(v);
  }
  color[u] = BLACK;

  F[u] = ++time;
  }*/

void BFS(int start){
  int u, v;

  for(u = 2; u <= n; u++ ){

    color[u] =  WHITE;

    D[u] = INT_MAX;

  }

  color[start] = GRAY;

  D[start] = 0;

  enQueue(start);
  while(isEmpty() != FALSE){

    u = deQueue();

    for( v = 1; v <= n; v++ ){
      if(color[v] == WHITE && G[u][v] == 1){

	color[v] = GRAY;

	D[v] = D[u] + 1;

	enQueue(v);
      }
    }
  }
}

void enQueue(int x){

  Q[tail] = x;

    if(tail == 100)tail = 0;
    
    else tail ++; 

}

int deQueue(){

  int x;

  x = Q[head];

  if(head == 100)head = 0;

  else head++;

  return x;
}


int isEmpty(){
  if(tail == head)return FALSE;

  else return TRUE;
}

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<k;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 <cstdio>
#include <queue>
using namespace std;
#define INF (1<<21)

int n, G[100][100], dist[100], visited[100];


int main(void) {
    int u, k, v, i, j;
    scanf("%d", &n);
    for (i = 0; i < n; i++)
        for (j = 0; j < n; j++) G[i][j] = 0;

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

    queue<int> q;
    q.push(0);
    while (!q.empty()) {
        u = q.front();
        q.pop();
        for (i = 0; i < n; i++) {
            if (G[u][i] == 0 || visited[i] == 1) continue;
            q.push(i);
            visited[i] = 1;
            dist[i] = dist[u] + 1;
        }
    }

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

    return 0;
}

C++: //Breadth First Search
#include <iostream>
#include <queue>

using namespace std;

static const int N = 100;

int d[N];

void bfs(vector<vector<int>> &graph, int u) {
    queue<int> q;
    q.push(u);
    d[u] = 0;

    while(!q.empty()) {
        int v = q.front();
        q.pop();
        for (auto w: graph[v]) {
            if(d[w] != -1) continue;
            q.push(w);
            d[w] = d[v] + 1;
        }
    }
}

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

    bfs(graph, 0);

    for(int i = 0; i < n; i++) cout << i+1 << " " << d[i] << endl;
    return 0;
}