Go: package main

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

var distance []int

type queue struct {
	q    []int
	head int
	tail int
}

func (q *queue) push(n int) {
	q.q[q.tail] = n
	q.tail++
}

func (q *queue) pop() int {
	q.head++
	return q.q[q.head-1]
}

func (q *queue) isEmpty() bool {
	return q.head == q.tail
}

func makeAdjList() [][]int {
	var n int
	fmt.Scanf("%d", &n)

	adj := make([][]int, n)
	for i := 0; i < n; i++ {
		adj[i] = make([]int, n)
	}

	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		sc.Scan()
		nodeInfo := strings.Split(sc.Text(), " ")
		outDegree, _ := strconv.Atoi(nodeInfo[1])

		if outDegree > 0 {
			for k := 0; k < outDegree; k++ {
				j, _ := strconv.Atoi(nodeInfo[k+2])
				j-- // convert 1 based to 0 based
				adj[i][j] = 1
			}
		}
	}

	return adj
}

func bfs(graph [][]int, s int) {
	distance = make([]int, len(graph))

	infty := -1
	for i := 0; i < len(distance); i++ {
		distance[i] = infty
	}
	distance[s] = 0

	q := &queue{make([]int, 1000), 0, 0}
	q.push(s)

	for !q.isEmpty() {
		u := q.pop()
		for i := 0; i < len(graph); i++ {
			if graph[u][i] == 0 {
				continue // u, i間に辺がない場合
			}
			if distance[i] != infty {
				continue // 訪問済みの場合
			}
			// 訪問するnodeの始点からの距離を設定し、訪問キューに入れる
			distance[i] = distance[u] + 1
			q.push(i)
		}
	}

	// print distance
	for i, d := range distance {
		fmt.Printf("%d %d\n", i+1, d)
	}
}

func main() {
	adj := makeAdjList()
	bfs(adj, 0)
}

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

using namespace std;

int n;
int u[102], k[102], t[102][102];
queue<int>Q;
vector<int>V;
int color[102];
int d[102];

void bfs(int s){
  for(int i = 1; i <= n; ++i){
    if(u[i] != s){
      color[u[i]] = 0;
      d[u[i]] = 150;
    }
  }
  d[s] = 0;
  int pi = 0;
  Q.push(s);
  while(!Q.empty()){
    int m = Q.front();
    Q.pop();
    for(int i = 1; i <= k[m]; ++i){
      if(color[t[m][i]] == 0){
        color[t[m][i]] = 2;
        d[t[m][i]] = d[m] + 1;
        pi = t[m][i];
        Q.push(t[m][i]);
      }
    }
    color[m] = 1;
  }
  for(int i = 1; i <= n; ++i){
    if(d[i] == 150){
      cout << i << " " << -1 << endl;
    }else{
      cout << i << " " << d[i] << endl;
    }
  }
  
}

int main(){
  cin >> n;
  for(int i = 1; i <= n; ++i){
    cin >> u[i] >> k[i];
    for(int j = 1; j <= k[i]; ++j){
      cin >> t[i][j];
    }
  }
  bfs(1);
}

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<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 <queue>
using namespace std;

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

    int adj_matrix[101][101] = {0};
    int visit[101] = {0};
    queue<int> q;
    int dist_from_start[101] = {0};
    for (int i = 1; i <= n; i++)
    {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++)
        {
            int x;
            cin >> x;
            adj_matrix[u][x] = 1;
        }
    }

    q.push(1);
    visit[1] = 1;
    while (!q.empty())
    {
        int now = q.front();
        for (int i = 1; i <= n; i++)
        {
            if (adj_matrix[now][i] == 1 && visit[i] == 0)
            {
                visit[i] = 1;
                q.push(i);
                dist_from_start[i] = dist_from_start[now] + 1;
            }
        }
        q.pop();
    }

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

    return 0;
}

C++: #include <iostream>
#include <cmath>
#include <set>
#include <string>
#include <algorithm>
#include <vector>
#include <bitset>
#include <iomanip>
#include <map>
#include <queue>
#include <numeric>

using std::cin;
using std::cout;
using std::endl;
using std::string;
using std::vector;
using std::bitset;

#define rep(i,n)    for(int i=0; i<(int)n; i++)
#define reps(i,s,e) for(int i=s; i<(int)e; i++)
typedef long double ld;
typedef long long ll;
typedef vector<int> vint;
typedef vector<ll> vll;
typedef std::pair<int, int> pii;
typedef std::pair<ll, ll> pll;

template<class T>
using Graph = vector<vector<T>>;

const int INT_BIG = ~(1<<28);

void printFixedDouble(double d, int fix) {
    cout << std::fixed;
    cout << std::setprecision(fix) << d << endl;
}

int main() {
    int nodeNum;
    cin >> nodeNum;
    Graph<int> nodes(nodeNum, vint());
    vint dist(nodeNum, -1);
    rep(i, nodeNum) {
        int u, k;
        cin >> u >> k;
        rep(j, k) {
            int v;
            cin >> v;
            nodes[u - 1].push_back(v - 1);
        }
    }

    std::queue<int> now;
    std::queue<int> next;
    next.push(0);
    int tmpdist = 0;
    while(!next.empty()) {
        now = next;
        next = std::queue<int>();
        while(!now.empty()) {
            int id = now.front();
            now.pop();
            if (dist[id] == -1) {
                dist[id] = tmpdist;
                for(auto& subid : nodes[id])
                next.push(subid);
            }
        }
        tmpdist++;
    }
    rep(i, nodeNum) {
        cout << i+1 << " " << dist[i] << endl;
    }
}

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

int n;
vector <int> G[101];
queue <int> Q;
int  d[100];
int  dis[101];


int visit(int x){
  int t,i;
  
  Q.push(x);
  dis[x] = 0;
  d[x] = 1;

  while(Q.empty() == false) {
    
    cout << "start Q" <<endl;

    t = Q.front();
    Q.pop();

    for(i=0; i<G[t].size();i++) {
      if(d[G[t][i]] == 0 ) {
	d[G[t][i]] = 1;
	dis[G[t][i]] = dis[t] + 1;

	Q.push(G[t][i]);
      }

    }
  }
}
    
int main() {
  
  int i,j,k,l,u,a,t;
  
  
  scanf("%d",&n);

  
  
  for(i=0;i<n;i++){
    d[i] = 0;
    dis[i] = -1;
    scanf("%d %d ",&k,&u);
    
    for(j=0;j<u;j++) {
      scanf("%d",&a);
      G[k-1].push_back(a-1);
      // printf("G[%d][%d] = 1\n",i,k-1);
    }
  }
  
  
  visit(0);

  

  for(i=0;i<n;i++) cout << i+1<<" " << dis[i] <<endl;



  return 0;

    
    
}