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;

int main() {
	int n;
	scanf("%d", &n);

	bool G[n + 1][n + 1];
	for (int i = 0; i <= n; ++i) {
		for (int j = 0; j <= n; ++j)
			G[i][j] = false;
	}

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

	int d[n + 1];
	for (int i = 0; i <= n; ++i)
		d[i] = -1;

	int color[n + 1];
	int WHITE = 0;
	int GRAY = 1;
	int BLACK = 2;
	for (int i = 0; i <= n; ++i)
		color[i] = WHITE;

	queue<int> Q;
	Q.push(1);
	d[1] = 0;
	color[1] = GRAY;

	while (Q.size() != 0) {
		int v = Q.front();
		for (int i = 1; i <= n; ++i) {
			if (G[v][i] && color[i] == WHITE) {
				Q.push(i);
				color[i] = GRAY;
				d[i] = d[v] + 1;
			}
		}
		Q.pop();
		color[v] = BLACK;
	}
	for (int i = 1; i <= n; ++i) {
		cout << i << " " << d[i] << endl;
	}
	return 0;
}

C++: #include<iostream>
#include<string.h>
#include<queue>
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define MAX 105
using namespace std;
int N;
//int M[MAX][MAX];
vector<int> V[MAX];
int D[MAX];
void BFS(int u)
{
	queue<int> Q;
	Q.push(u);
	D[u]=0;
	while(!Q.empty())
	{
		int i=Q.front();
		Q.pop();
		/*FOR(j,1,N)
			if(M[i][j]&&D[j]==MAX)
			{
				Q.push(j);
				D[j]=D[i]+1;
			}
		*/
		for(int j=0;j<V[i].size();j++)
			if(D[V[i][j]]==MAX)
			{
				Q.push(V[i][j]);
				D[V[i][j]]=D[i]+1;
			}
	}
	FOR(i,1,N)
		printf("%d %d\n",i,(D[i]==MAX)?-1:D[i]);
		//cout<<i<<" "<<((D[i]==MAX)?(-1):D[i])<<"\n";
}
int main()
{
	//memset(M,0,sizeof(M));
	scanf("%d",&N);
	FOR(i,1,N)
		D[i]=MAX;
	int u,k,v;
	FOR(i,1,N)
	{
		scanf("%d %d",&u,&k);
		FOR(j,1,k)
		{
			scanf("%d",&v);
			V[u].push_back(v);
		}
	}
	BFS(1);
	return 0;
}