Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	visitedAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		visitedAt: -1,
		adjs: adjs,
	}
}

func (v *vertex) isVisited() bool {
	return v.visitedAt >= 0
}

func bfs(id vertexId, vqueue []vertexId, vertices []vertex) {
	vertex := &vertices[id-1]
	for _, vid := range vertex.adjs {
		if !vertices[vid-1].isVisited() {
			(&vertices[vid-1]).visitedAt = vertex.visitedAt+1
			vqueue = append(vqueue, vid)
		}
	}
	if len(vqueue) > 0 {
		nextId := vqueue[0]
		nextVqueue := vqueue[1:]
		bfs(nextId, nextVqueue, vertices)
	}
}

func solveBfs(vertices []vertex) {
	vertex := &vertices[0]
	vertex.visitedAt = 0
	vqueue := make([]vertexId, 0)
	bfs(vertex.id, vqueue, vertices)
}

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

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

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	solveBfs(vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d\n", vertices[i].id, vertices[i].visitedAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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

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);
  int i;

  for(i=0;i<n;i++)
    d[i]=INFTY;
  d[s]=0;
  int u;
  while(!q.empty()){
    u=q.front();
    q.pop();
    int v;
    for(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(i=0;i<n;i++){
    cout<<i+1<<" "<<((d[i]==INFTY)?(-1):d[i])<<endl;
  }
}

int main(){
  int u,k,v,i,j;

  cin>>n;

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

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

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

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

  bfs(0);

  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

// 辺を表す構造体
struct edge{
    int to, cost;
};

// キューに入れる頂点を表す構造体
struct node{
    int id, cost;
};

constexpr int INF = (1 << 30) - 1;

// s:=始点 cost:=始点からの最短経路長がここに書き込まれる g:=隣接リストでグラフを渡す
void breadth_first_search(int s, vector<int>& cost, const vector< vector<edge> >& g){
    cost.resize(g.size());
    fill(cost.begin(), cost.end(), INF);
    cost[s] = 0;
    queue<node> que;
    que.push({s, 0});

    while(!que.empty()){
        node now = que.front();
        que.pop();
        if(cost[now.id] < now.cost){
            continue;
        }
        for(auto& e : g[now.id]){
            if(cost[e.to] > now.cost + e.cost){
                cost[e.to] = now.cost + e.cost;
                que.push({e.to, now.cost + e.cost});
            }
        }
    }

    return;
}

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

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

    vector<int> cost;
    breadth_first_search(0, cost, g);

    for(int i = 0 ; i < n ; ++i){
        cout << i + 1 << " ";
        if(cost[i] < INF){
            cout << cost[i] << endl;
        }else{
            cout << -1 << endl;
        }
    }

    return 0;
}

C++: #include<iostream>
#include<vector>
#include<queue>

using namespace std;

int n;
int u,k,t;
int d[100];
int dis=0;
int inf = -1;
vector<int> G[100];
queue<int> q;

void bfs(int x){
    q.push(x);
    while(!q.empty()){
        int u = q.front();q.pop();
        for(int i=0;i<G[u].size();i++){
            int v = G[u][i];
            if(d[v] == inf){
                d[v] = d[u] + 1;
                q.push(v);
            }
        }
    }
}

int main(){
    cin >> n;
    for(int i=0;i<n;i++){
        cin >> u >> k;
        u--;
        for(int j=0;j<k;j++){
            cin >> t;
            t--;
            G[u].push_back(t);
        }
    }
    fill(d,d+n,inf);
    d[0] = 0;
    bfs(0);
    for(int i=0;i<n;i++){
        cout << i+1 << " " << d[i] << endl;
    }
    return 0;
}

C++: #include<cstdio>
#include<queue>
using namespace std;
const char N_MAX = 105;
bool matrix[N_MAX][N_MAX];
char n;
char length = 0;
queue<char> que;
struct Node{
    char state;//0:undiscovered 1:active 2:end
    char path;
};
Node V[N_MAX];
char next(char num, char found){
    for(char i=found;i<n;i++){
        if(matrix[num][i]&&V[i].state==0){
            return i;
        }
    }
    return -1;
}
void buildMatrix(){
	for(char i=0; i<n;i++){
		int degree, index;
		scanf("%u%u", &index, &degree);
		for(char j=0; j<degree; j++){
			int temp;
			scanf("%d", &temp);
			matrix[index-1][temp-1] = true;
		}
	}
}

void bfs() {
    que.push(0);
    V[0].path = length = 0;
    V[0].state = 1;
    while(!que.empty()) {
        char active = que.front();
        char nex = next(active, 0);
        while(nex != -1) {
            que.push(nex);
            V[nex].path = V[active].path+1;
            V[nex].state = 1;
            nex = next(active, nex + 1);
        }
        V[active].state = 2;
        que.pop();
    }
}

int main(){
    scanf("%d", &n);
    for(char i=1;i<n;i++){
        V[i].path=-1;
    }
    buildMatrix();
    bfs();
    for(char i =0;i<n;i++){
        printf("%d %d\n", i+1, V[i].path);
    }
    return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define reps(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
const ll mod = ll(1e9) + 7;
const int INF = int(1e9);
int main()
{
    int d[100][100];
    int N;
    cin>>N;
    rep(i,N){
        rep(j,N)d[i][j]=INF;
    }
    vector<int>edge(N);
    rep(i,N){
        int tmp;
        cin>>tmp;
        tmp--;
        int n;
        cin>>n;
        rep(j,n){
            int a;
            cin>>a;
            a--;
            d[tmp][a]=1;
        }
    }
    rep(i,N)d[i][i]=0;
    rep(k,N){
        rep(i,N){
            rep(j,N){
                d[i][j]=min(d[i][j],d[i][k]+d[k][j]);
            }
        }
    }
    rep(i,N){
        if(d[0][i]<INF){
            cout<<i+1<<" "<<d[0][i]<<endl;
        }else{
            cout<<i+1<<" "<<-1<<endl;
        }
    }

    return 0;
}