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<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;
#define rep(i, n) for (int i=0; i < (int)(n); i++)
using ull = unsigned long long;
using ll = long long;



int main() {
    int N;
    cin >> N;

    vector<vector<int>> G(N+1);
    rep(i, N) {
        int u, k, vi;
        cin >> u >> k;
        rep(j, k) cin >> vi, G[u].push_back(vi);
    }

    int dist[N+1], d=0;
    rep(i, N+1) dist[i] = -1;

    queue<int> que;
    que.push(1);
    dist[1] = 0;

    while (que.size() > 0) {
        int v = que.front();
        que.pop();

        for (auto next_v: G[v]) {
            if (dist[next_v] == -1) {
                que.push(next_v);
                dist[next_v] = dist[v] + 1;
            }
        }
    }

    for (int i=1; i<=N; i++) cout << i << " " << 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 <iostream>
#include <queue> 
using namespace std;
int G[100][100];
int d[100];
int color[100];
int n;
queue<int> qu;
void bfs ()
{
    color[0] = 1;
    d[0] = 0;
    qu.push(0);
    while (!qu.empty())
    { 
        int u = qu.front(); qu.pop();
        for (int i = 0; i < n; i++)
        {
            if (G[u][i] == 1 && color[i] == 0)
            {
                color[i] = 1;
                d[i] = d[u] + 1;
                qu.push(i);
            }
        }
        color[u] = 2;
    } 
    return;
}

int main()
{
    int k, u, v;
    cin>>n;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            G[i][j] = 0; 
        }  
    } 

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

    for (int i = 0; i < n; i++)
    {
        d[i] = -1; 
        color[i] = 0;
    } 
    bfs();
    for (int i = 0; i < n; i++)
    {
         cout<< i+1<<d[i]<<endl;
    } 
    return 0;
}

C++: #include<stdio.h>
#include<stack>
#include<iostream>
#include<string>
using namespace std;

int n = 0;
int u = 0;
int k[101];
int v[101][101];
int Short[101] = { 0 };
//into n = 0;
int p = 0;
int fptr = 0;
int lptr = 0;
int x1[10000];
int y1[10000];
void Enqueue(int y, int x)
{
	x1[lptr] = x;
	y1[lptr] = y;
	lptr = (lptr + 1) % n;
}
void bfs(int l) {
	int i;
	while (fptr!=lptr) {
		l=x1[fptr];
		p=y1[fptr];
		fptr = (fptr + 1) % n;
		if(Short[l]!=-1){
			continue;
		}
		for(i=0;i<k[l];i++){
			if(v[l][i]){
				Enqueue(p+1,v[l][i]);
			}
		}
		//Enqueue(v[l][in]);
		Short[l]=++p;
	}
}
int main()
{
	int i;
	int j;
	cin >> n;
	for (i = 0; i < n; i++) {
		cin >> u;
		cin >> k[u];
		for (j = 0; j < k[u]; j++) {
			cin >> v[u][j];
		}
	}
	Enqueue(-1,1);
	for(i=0;i<n+1;i++){
		Short[i]=-1;
	}
	bfs(0);

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