Go: package main

import "fmt"

type container struct {
	data []int
}

func (c *container) queue(v int) {
	c.data = append(c.data, v)
}
func (c *container) dequeue(p *int) bool {
	if p == nil || len(c.data) == 0 {
		return false
	}
	*p = c.data[0]
	c.data = c.data[1:len(c.data)]
	return true
}

func main() {
	var n int
	fmt.Scan(&n)
	g := make([][]int, n+1) // 1-indexed
	d := make([]int, n+1)   // 1-indexed
	for i := 1; i <= n; i++ {
		d[i] = -1
		var u, k, v int
		fmt.Scan(&u, &k)
		for j := 0; j < k; j++ {
			fmt.Scan(&v)
			g[u] = append(g[u], v)
		}
	}

	var q container
	d[1] = 0
	q.queue(1)

for len(q.data) > 0  { // 幅優先探索
		var v int
		q.dequeue(&v)
		for i := 0; i < len(g[v]); i++ {
			nv := g[v][i]
		if d[nv] == -1 { // 未訪問
				q.queue(nv)
				d[nv] = d[v] + 1
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d\n", i, d[i])
	}
}

C++: #include<iostream>
#include<queue>
#include<vector>
#define INF (int)1e9 + 7
using namespace std;
int n;
vector<pair<int, int> > adj[10000];
void dijkstra();
int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v; //vertex cost
            cin >> v;
            adj[u].push_back(make_pair(1, v));
        }
    }
    dijkstra();
    return 0;
}
void dijkstra() {
    int dist[n + 1];
    dist[1] = 0;
    for (int i = 2; i <= n; i++) {
        dist[i] = INF;
    }
    priority_queue<pair<int, int> > q;
    q.push(make_pair(0, 1));
    while (!q.empty()) {
        int u = q.top().second;
        //int co = -q.top().first;
        q.pop();
        for (int i = 0; i < adj[u].size(); i++) {
            int v = adj[u][i].second; //adj[u]のi番目の番号
            int co2 = adj[u][i].first;
            if (dist[u] + co2 < dist[v]) {
                dist[v] = co2 + dist[u];
                q.push(make_pair(-dist[v] ,v));
            }
        }
    }
    for (int i = 1; i <= n; i++) {
        cout << i << " ";
        if (dist[i] == (int)1e9 + 7) {
            cout << -1 << endl;
        } else {
            cout << dist[i] << endl;
        }
    }
}

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 <vector>
using namespace std;
 
static const  int N =  100;
static const  int no =  -1;
 
int graph[N][N] = {{}};
int d[N] = {};
int n;
 
void bfs(int v){
  vector<int> V;
  V.push_back(v);
  int u;
    for(int i = 1;i <= n; i++){
      d[i] = no;
     
}
  d[v] = 0;
 
  while(!V.empty()){
    u = V.front();
    V.erase(V.begin());
 
    for(int i = 1;i <= n; i++){
      if(graph[u][i] == 0) continue;
      if(d[i] != no) continue;
      d[i] = d[u] +1;
      V.push_back(i);
    }
  }
}
 
 
int main(){
  int u,v,k;
  cin >> n ;
 
  for(int i = 0; i < n; i++){
    cin >> u >> k ;
    for(int j = 0; j < k ; j++){
      cin >> v;
      graph[u][v] = 1;
    }
  }
 
 
  bfs(1);
 
  for(int i = 1;i <= n; i++){
    cout << i << " " << d[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);
    int i;
    for(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(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 <stdio.h>
#include <iostream>
using namespace std;

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

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

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 id)
{
	if (id == check_id) return -1;
	else check_id = id;

	if (id == u) {
		check_id = 0;
		return 0;
	}

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

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