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 <numeric>
#include <cassert>
#include <queue>

const int MAXINT = 1000000000;

void bfs(std::vector<std::vector<int> >& adj_list, std::vector<int>& d, int root = 0 ){
  std::queue<int> target_q;
  // std::queue<int> dist_q;
  target_q.push(root);
  d[root] = 0;
  // dist_q.push(0;)
  while(!target_q.empty()){
    int vtx = target_q.front(); target_q.pop();
    for(int const&  u : adj_list[vtx]){
      target_q.push(u);
      if(d[vtx] + 1 < d[u]){
        // std::cout<< "/* message */" << std::endl;
        d[u] = d[vtx] + 1;
      }
    }
  }
}


int main(int argc, char const *argv[]) {
  int n; // .. 100
  std::cin >> n;
  std::vector<std::vector<int> > adj_list(n);
  std::vector<int> d(n, MAXINT);

  for(int q=0; q<n; ++q){
    int i_plus_1, k;
    std::cin >> i_plus_1;
    std::cin >> k;
    for(int p=0; p<k; ++p){
      int j_plus_1;
      std::cin >> j_plus_1;
      // adj[i_plus_1-1][j_plus_1-1] = true;
      adj_list[i_plus_1 - 1].push_back(j_plus_1-1);
    }
  }
  bfs(adj_list, d, 0);

  for(int i=0; i<n; ++i){

    // if(d[i] < MAXINT){
      std::cout << (i+1)
        << " " << (d[i]==MAXINT ? -1 : d[i])
        << std::endl;
  }


  // for(auto it = adj_list.begin(); it != adj_list.end(); ++it){
  //   std::cout << ": ";
  //   for(auto jt = (*it).begin(); jt != (*it).end(); ++jt){
  //     std::cout << (*jt) << ' ';
  //   }
  //   std::cout << std::endl;
  // }

  return 0;
}

C++: #include<iostream>
#include<cstdio>
#define INF 1000000
#define NIL -2
#define GRAY -3
#define WHITE -4
#define BRACK -5

using namespace std;

int n;
int M[101][101];
int d[101];//重み
//int p[101];//親
int color[101];

void Dijkstra(int u) {
	//cout << u << endl;
	color[u] = BRACK;

	//重みの更新
	for (int i = 1; i <= n; i++) {
		if (color[i] != BRACK && M[u][i] != 0) {
			color[i] = GRAY;
			if ((d[u] + M[u][i]) < d[i]) {
				d[i] = d[u] + M[u][i];
			}
		}
		//cout << d[i] << " ";
	}

	//cout << endl;

	int min = -1;
	d[min] = 100000;


	for (int v = 1; v <= n; v++) {
		if (color[v] != BRACK) {
			if (d[v] < d[min]) {
				min = v;
			}
			else {
				color[v] = WHITE;
			}
		}
	}

	if (min != -1) {
		Dijkstra(min);
	}
}

int main() {
	cin >> n;
	int v, k, g, weight; //v = 節点番号　g = 次数

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

	for (int i = 1; i <= n; i++) {
		cin >> v >> g;
		for (int j = 1; j <= g; j++) {
			cin >> k;
			M[i][k] = 1;
		}
	}

	for (int i = 1; i <= n; i++) {
		color[i] = WHITE;
	}

	for (int i = 1; i <= n; i++) {
		d[i] = INF;
		//cout << d[i] << " ";
	}

	d[1] = 0;


	//関数
	Dijkstra(1);


	for (int i = 1; i <= n; i++) {
		if (d[i] == INF) {
			d[i] = -1;
		}
		cout << i << " " << d[i] << endl;
	}

	return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;
static const int N = 100;
static const int INF = (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] = INF;
	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] != INF)continue;
			d[v] = d[u]+1;
			q.push(v);
		}
	}
	for(int i=0;i<n;i++){
		cout << i+1 << " " <<((d[i] == INF)?(-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;
const int MAX = 100;
int n, G[MAX + 1][MAX + 1];
bool book[MAX + 1] = { false };
int path[MAX + 1];
void breathFSearch(int orign)
{
	queue<int> Q;
	Q.push(orign);
	book[orign] = true;
	while (!Q.empty())
	{
		int u = Q.front();
		for (int v = 1; v <= n; v++)
		{
			if (G[u][v] && !book[v])
			{
				Q.push(v);
				book[v] = true;
				if(path[u]!=-1)
					path[v] = path[u]+1;
			}
		}
		Q.pop();
	}
}
int main()
{
	cin >> n;
	for (int i = 1; i <= n; i++)
	{
		int u, d;
		cin >> u >> d;
		for (int j = 1; j <= d; j++)
		{
			int v;
			cin >> v;
			G[u][v] = 1;
		}
	}
	for (int i = 1; i <= n; i++)
		path[i] = -1;
	path[1] = 0;
	for(int i=1;i<=n;i++)
		if(!book[i])
			breathFSearch(i);
	for (int i = 1; i <= n; i++)
		cout << i << " " << path[i] << endl;
}