Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)

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

		d[i+1] = -1
	}

	q := [][]int{}
	q = append(q, []int{1, 0})
	for len(q) > 0 {
		pop := q[0]
		if len(q) > 1 {
			q = q[1:]
		} else {
			q = [][]int{}
		}
		if d[pop[0]] >= 0 {
			continue
		}
		d[pop[0]] = pop[1]

		for j := 0; j < len(g[pop[0]]); j++ {
			q = append(q, []int{g[pop[0]][j], pop[1]+1})
		}
	}

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

C++: #include<iostream>
#include<cstdio>
#include<algorithm>
#include<queue>
using namespace std;
#define N 1000
bool M[N][N];

int main(){
    int n,u,k,v;
    queue<int> Q;
 
    cin >> n;
    for(int i=0;i<n;i++){
	cin >> u >> k;
	u--;
	for(int j=0;j<k;j++){
	    cin >> v;
	    v--;
	    M[u][v]=true;
	}
    }
   
    int d[N]={0};
    Q.push(0);
    while(!Q.empty()){
	u=Q.front();
	Q.pop();
	for(int i=0;i<n;i++){
	    if(M[u][i] && d[i]==0){
		d[i]=d[u]+1;
		Q.push(i);
	    }
	}
    }

    for(int i=0;i<n;i++){
	if(i!=0 && d[i]==0) d[i]=-1;
	printf("%d %d\n",i+1,d[i]);
    }

    return 0;
}

C++: #include <iostream>
#include <ios>
#include <vector>
#include <utility>

using namespace std;

void read_data(int n, vector<vector<int>> & Es){
    int u = 0, k = 0, v = 0;
    while (n--){
        cin >> u;
        cin >> k;
        while (k--){
            cin >> v;
            Es[u - 1].push_back(v - 1);
        }
    }
}

void wfs(int node, vector<int> & dist, vector<vector<int>> & Es){
    int d = 0;
    vector<int> frontiers;
    frontiers.push_back(node);
    while (!frontiers.empty()){
        ++d;
        vector<int> new_frontiers;
        for (auto u : frontiers){
            for (auto v : Es[u]){
                if (dist[v] == -1){
                    dist[v] = d;
                    new_frontiers.push_back(v);
                }
            }
        }
        frontiers = move(new_frontiers);
    }
}

int main()
{
    ios::sync_with_stdio(false);
    int n = 0;
    cin >> n;
    vector< vector<int> > Es(n);
    vector<int> dist(n, -1);
    read_data(n, Es);
    wfs(0, dist, Es);
    for (int i = 0; i != n; ++i) cout << i + 1 << ' ' << dist[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]; // ?????¢??§?¨??????¶???(color)???????????????

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 <cstdio>
#include <queue>
#include <vector>

using namespace std;
#define MAX_N (105)
typedef pair<int, int> P;

int n;
vector<int> G[MAX_N];
int dist[MAX_N];
int main()
{
    scanf("%d", &n);
    for ( int i = 0; i < n; i++ ) {
	int u, k;
	scanf("%d %d", &u, &k);
	u--;

	for ( int j = 0; j < k; j++ ) {
	    int v;
	    scanf("%d", &v);
	    v--;
	    G[u].push_back( v );
	}
    }

    for ( int i = 0; i < n; i++ ) dist[i] = -1;
    dist[0] = 0;

    queue<int> Q;
    Q.push( 0 );

    while ( !Q.empty() ) {
	int cur = Q.front();
	Q.pop();
	for ( int i = 0; i < G[cur].size(); i++ ) {
	    int next = G[cur][i];
	    if ( dist[next] == -1 ) {
		dist[next] = dist[cur] + 1;
		Q.push( next );
	    }
	}
    }

    for ( int i = 0; i < n; i++ ) {
	printf("%d %d\n", i+1, dist[i]);
    }

    return 0;
}

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

using namespace std;

#define FOR(i,s,e) for((i)=(s);(i)<(int)(e);(i)++)
#define REP(i,e) FOR(i,0,e)

#define all(o) (o).begin(), (o).end()
#define psb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))

typedef long long ll;
typedef pair<int, int> PII;

const double EPS = 1e-10;

typedef struct edge_def {
  int from;
  int to;
  int cost;

  edge_def(int _from, int _to, int _cost) {
    from = _from;
    to   = _to;
    cost = _cost;
  }
} edge;

const int INF = INT_MAX;
const int V = 100;
int n, t;
vector<edge> es[V];
int d[V];

void dijkstra(int s) {
  int i;
  priority_queue<PII, vector<PII>, greater<PII > > q;
  for (i=0; i<n; i++) d[i] = INF;
  d[s] = 0;
  q.push(PII(0, s));

  while (q.size()) {
    PII p = q.top();
    q.pop();
    int v = p.second;

    if (d[v] < p.first) continue;

    for (i=0; i<(int)es[v].size(); i++) {
      edge e = es[v][i];
      if (d[e.to] > d[v] + e.cost) {
        d[e.to] = d[v] + e.cost; 
        q.push(PII(d[e.to], e.to));
      }
    }
  }
}

int main() {
  int i, j;
  memset(d, 0xff, sizeof(d));
  for (i=0; i<V; i++) es[i].clear();

  scanf("%d ", &n);
  for (i=0; i<n; i++) {
    int u, v, k;
    scanf("%d ", &u);
    scanf("%d ", &k);
    for (j=0; j<k; j++) {
      scanf("%d ", &v);
      es[u-1].psb(edge(u-1, v-1, 1));
    }
  }

  dijkstra(0);

  for (i=0; i<n; i++) {
    if (d[i]==INF) d[i] = -1;
    printf("%d %d\n", i+1, d[i]);
  }

	return 0;
}

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

using namespace std;

static const int N = 100;
static const int NEW = 0;
static const int VISITING = 1;
static const int OLD = 2;

int n, m[N][N] = {0}, t;
int color[N] = { 0 }, t1[N] = { 0 }, t2[N] = {0};

void getMatrix()
{
	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;
			m[u-1][v-1] = 1;
		}
	}
}

int nxt(int idx)
{
	for (int i = 0; i < n; ++i)
	{
		if (1 == m[idx][i] && color[i] == NEW)
			return i;
	}
	return -1;
}

void dfs_visit(int idx)
{
	stack<int> s;
	s.push(idx);
	color[idx] = VISITING;
	t1[idx] = t++;


	while (!s.empty())
	{
		int u = s.top();
		int v = nxt(u);
		if (-1 != v)
		{
			color[v] = VISITING;
			t1[v] = t++;
			s.push(v);
		}
		else
		{
			s.pop();
			color[u] = OLD;
			t2[u] = t++;
		}
	}
}

void dfs()
{
	t = 1;

	for (int i = 0; i < n; ++i)
		color[i] = NEW;

	for (int i = 0; i < n; ++i)
	{
		if (color[i] == NEW)
			dfs_visit(i);
	}

	for (int i = 0; i < n; ++i)
	{
		cout << i + 1 << " " << t1[i] << " " << t2[i] << endl;
	}
}

int dist[N];

void bfs(int idx)
{
	queue<int> q;
	q.push(idx);

	for (int i = 0; i < n; ++i)
		dist[i] = INT_MAX;
	dist[idx] = 0;

	int u;
	while (!q.empty())
	{
		u = q.front(); q.pop();
		for (int i = 0; i < n; ++i)
		{
			if (m[u][i] == 0) continue;
			if (dist[i] != INT_MAX) continue;
			dist[i] = dist[u] + 1;
			q.push(i);
		}
	}
	for (int i = 0; i < n; ++i)
	{
		cout << i + 1 << " " <<( (dist[i] == INT_MAX) ? (-1) : dist[i]) << endl;
	}
}


int main()
{
	getMatrix();
	bfs(0);
}