Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

type AdjacentList struct {
	matrix [][]int
}

func NewEmptyAdjacentList(dim int) *AdjacentList {
	matrix := make([][]int, dim)
	for i := 0; i < dim; i++ {
		matrix[i] = make([]int, dim)
	}
	return &AdjacentList{matrix: matrix}
}

func (al *AdjacentList) set(node int, adjacent int) {
	al.matrix[node-1][adjacent-1] = 1
}

func (al *AdjacentList) findAdjacentsFor(node int) []int {
	adjacents := []int{}
	for i, v := range al.matrix[node-1] {
		if v == 1 {
			adjacents = append(adjacents, i+1)
		}
	}
	return adjacents
}

type DistanceList struct {
	list []int
}

func NewDistanceList(dim int) *DistanceList {
	list := make([]int, dim)
	for i := 0; i < dim; i++ {
		list[i] = -1
	}
	return &DistanceList{list: list}
}

func (dl *DistanceList) set(node int, distance int) {
	dl.list[node-1] = distance
}

func (dl *DistanceList) get(node int) int {
	return dl.list[node-1]
}

func (dl *DistanceList) isVisited(node int) bool {
	return dl.list[node-1] >= 0
}

type Position struct {
	node     int
	distance int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	dim, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	al := NewEmptyAdjacentList(dim)

	for i := 1; i <= dim; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}

		adjacentNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		for j := 0; j < adjacentNum; j++ {
			adjacent, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			al.set(node, adjacent)
		}
	}

	dl := NewDistanceList(dim)

	bfs(al, dl)

	for i := 1; i <= dim; i++ {
		fmt.Printf("%d %d\n", i, dl.get(i))
	}
}

func bfs(al *AdjacentList, dl *DistanceList) {
	stack := []Position{Position{node: 1, distance: 0}}
	for len(stack) > 0 {
		currentPosition := stack[0]
		stack = stack[1:]
		if !dl.isVisited(currentPosition.node) {
			dl.set(currentPosition.node, currentPosition.distance)
		}
		for _, v := range al.findAdjacentsFor(currentPosition.node) {
			if !dl.isVisited(v) {
				stack = append(stack, Position{node: v, distance: currentPosition.distance + 1})
			}
		}
	}
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include <iostream>
#include <queue>
using namespace std;

const int INF = -1;
int n;
int a[100][100], d[100];

int dist(int id) {
	int t = 0;
	queue<int> pd;

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

	pd.push(1);
	d[0] = 0;

	while (pd.size()) {
		int id1 = pd.front();
		pd.pop();

		if (id1 == id)
			break;

		for (int i = 0; i < n; i++) {
			if (a[id1 - 1][i] && d[i] == INF) {
				pd.push(i + 1);
				d[i] = d[id1 - 1] + 1;
			}
		}
	}
	return d[id - 1];
}

int main()
{
	cin >> n;

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

	for (int i = 1; i < n + 1; i++) {
		int dmin = dist(i);
		cout << i << " " << dmin << endl;
	}

	return 0;
}

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

class Adjl{
private:
	int u;
	int k;
	Adjl **next;
public:
	Adjl(int u);
	~Adjl(){ if (next != NULL) delete[] next; }
	void setV(int k, Adjl *vk);
	int breadthFirstSearch(int u, int id);
	void print(int id);
};

Adjl::Adjl(int u)
{
	this->u = u;
	k = 0;
	next = NULL;
}

void Adjl::setV(int k, Adjl *vk)
{
	if (this->k == 0) next = new Adjl*[k];
	next[this->k] = vk;
	(this->k)++;
}

int Adjl::breadthFirstSearch(int u, int id)
{
	if (id == this->u) return 0;
	int d_min = -1;
	for (int i = 0; i < k; i++) {
		if (next[i]->u == u) continue;
		int d = next[i]->breadthFirstSearch(u, id);
		if (d == -1) continue;
		if (d_min == -1) d_min = d + 1;
		else d_min = min(d + 1, d_min);
	}
	return d_min;
}

void Adjl::print(int id)
{
	cout << id << " " << breadthFirstSearch(u, id) << endl;
}

int main(void)
{
	int n;
	cin >> n;
	
	Adjl **adjl = new Adjl*[n];
	int check[100] = {0};

	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		if (check[i] == 0) {
			adjl[i] = new Adjl(u);
			check[i] = 1;
		}
		check[i] = 1;
		for (int j = 0; j < k; j++) {
			int vk;
			cin >> vk;
			if (check[vk - 1] == 0) {
				adjl[vk - 1] = new Adjl(vk);
				check[vk - 1] = 1;
			}
			adjl[i]->setV(k, adjl[vk - 1]);
		}
	}

	for (int i = 1; i <= n; i++) {
		adjl[0]->print(i);
	}

	delete[] adjl;
	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 <vector>
#include <queue>
#include <cstring>
#define INFTY 1000000000
using namespace std;
bool list[100][100];
int ti[100];
int n;

void bfs(int now){
	queue<int> next;
	next.push(now);
	while(next.size()!=0){
		now=next.front();	next.pop();
		for(int i=0;i<n;i++){
			if(list[now][i]&&ti[i]==INFTY){
				ti[i]=ti[now]+1;
				next.push(i);
			}
		}
	}
}

int main(){
	for(int i=0;i<100;i++){
		for(int j=0;j<100;j++)	list[i][j]=false;
		ti[i]=INFTY;
	}
	cin>>n;
	int id,num,ne;
	for(int i=0;i<n;i++){
		cin>>id>>num;
		id--;
		for(int j=0;j<num;j++){
			cin>>ne;
			list[id][ne-1]=true;
		}
	}
	for(int i=0;i<n;i++){
		if(ti[i]==INFTY){
			ti[i]=0;
			bfs(i);
		}
	}
	for(int i=0;i<n;i++){
		cout<<i+1<<" "<<((ti[i]==INFTY)?(-1):ti[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()){
    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 <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

vector<int>to[105];
int main(){
  int n;
  cin>>n;
  rep(i,n){
    int u,k;
    cin>>u>>k;
    --u;
    rep(j,k){
      int v;
      cin>>v;
      --v;
      to[u].push_back(v);
      //to[v].push_back(u);
    }
  }
  queue<int>q;
  vector<int>dist(n,-1);
  dist[0]=0;
  q.push(0);
  while(!q.empty()){
    int v=q.front();q.pop();
    for(int u:to[v]){
      if(dist[u]!=-1)continue;
      dist[u]=dist[v]+1;
      q.push(u);
    }
  }
  rep(i,n)cout<<i+1<<" "<<dist[i]<<endl;
  return 0;
}