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 <queue>

using namespace std;

int n,u,k,v,x;
int a[101][101]={};
int d[101]={0};
queue<int> q;

int main()
{
    cin >> n;
    for(int i=0;i<n;i++)
    {
        cin >> u >> k;
        u-=1;
        for(int j=0;j<k;j++)
        {
            cin >> v;
            v-=1;
            a[u][v]=1;
        }
    }
    q.push(0);
    while(!q.empty())
    {
        x=q.front();
        q.pop();
        for(int i=0;i<n;i++)
        {
            if(a[x][i]==0) continue;
            if(d[i]!=0) continue;
            d[i]=d[x]+1;
            q.push(i);
        }
    }
    cout << 1 << " " << 0 << endl;
    for(int i=1;i<n;i++)
    {
        cout << i+1 << " ";
        if(d[i]==0) cout << -1;
        else cout << d[i];
        cout << endl;
    }
    return 0;
}

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



int main(){
  const int MX=1e9+7;
  int a[1000][1000];
  fill(&a[0][0],&a[999][999],MX);
  for(int i=0;i<1000;i++){
    a[i][i]=0;
  }
  int n;
  cin>>n;
  for(int i=0;i<n;i++){
    int w;
    cin>>w;
    int m;
    cin>>m;
    for(int t=0;t<m;t++){
      int e;
      cin>>e;
      a[w][e]=1;
    }
  }
  for(int i=1;i<=n;i++){
    for(int t=1;t<=n;t++){
      for(int k=1;k<=n;k++){
	a[t][k]=min(a[t][k],a[t][i]+a[i][k]);
      }
    }
  }
  for(int i=1;i<=n;i++){
    cout<<i<<" "<<(a[1][i]==MX? -1:a[1][i])<<endl;
  }


  
  return 0;
}

C++: #include <iostream>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
#include <algorithm>

typedef long long ll;

using namespace std;

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

C++: #include <bits/stdc++.h>
#define REP(i, n) for(int i = 0; i < (n); i++)
#define REP1(i, n) for(int i = 1; i <= (n); i++)
#define REPD(i,a,b) for (int i=(a);i<(b);i++)
#define ALL(v) (v).begin(), (v).end()
using namespace std;
typedef long long ll;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef set<int> si;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef pair<int, int> pi;
typedef queue<int> qi;
typedef queue<pi> qpi;
typedef pair<ll, ll> pll;
typedef queue<pll> qpll;
typedef vector<pi> vpi;
typedef vector<pll> vpll;
const int mod = 1000000007;
const int INF = 1001001001;
// 小数点　<< fixed << setprecision(0) <<
// sort降順　sort(ALL(),greater<int>());
// 円周率　M_PI
// 文字判定　isupper islower
// 順列　do {} while(next_permutation(ALL(X)));
// 最大値　LLONG_MAX
// a内でx以上　auto iter = lower_bound(ALL(a), x);
// a内でxより大きい　auto iter = upper_bound(ALL(a), x);
int dx[8] = {1, 0, -1, 0, 1, 1, -1, -1};
int dy[8] = {0, 1, 0, -1, 1, -1, 1, -1};
struct edge {
    int from; //出発点
    int to;   //到達点
    int cost; //移動コスト
};
typedef struct edge se;
typedef vector<edge> ve;
unsigned euclidean_gcd(unsigned a, unsigned b) {
  if(a < b) return euclidean_gcd(b, a);
  unsigned r;
  while ((r=a%b)) {
    a = b;
    b = r;
  }
  return b;
}

int main() {
  int n;
  cin >> n;
  vvi tree(n);
  REP(i,n) {
    int u,k;
    cin >> u >> k;
    REP(j,k) {
      int v;
      cin >> v;
      tree[i].push_back(v-1);
    }
  }
  qi que;
  vi check(n,-1);
  que.push(0);
  check[0]=0;
  while(!que.empty()) {
    int x=que.front();
    int cnt=check[x];
    que.pop();
    for(auto i:tree[x]) {
      if(check[i]!=-1) continue;
      check[i]=cnt+1;
      que.push(i);
    }
  }
  REP(i,n) {
    cout << i+1 << " " << check[i] << endl;
  }
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
 
using ll = long long;
using ld = long double;
#define FOR(i, m, n) for (int i = (m); i < (n); i++)
#define FORR(i, m, n) for (int i = (m); i >= (n); i--)
#define REP(i, n) FOR(i, 0, (n))
#define REPR(i, n) FORR(i, (n) - 1, 0)
#define REP1(i, n) FOR(i, 1, (n) + 1)
#define REPS(c, s) for (char c : s)
#define ALL(c) (c).begin(), (c).end()
#define SORT(c) sort(ALL(c))
#define REV(c) reverse(ALL(c))
#define sz(v) (int)v.size()
#define endl '\n'
template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
template<class T> inline void printv(vector<T>& v) {int n = sz(v); REP(i, n) cout << v[i] << (i == n - 1 ? endl : ' ');}
const int MOD = 1000000007;
const int INF = 1000000001;
const ll LINF = 1000000001000000001LL;
 
void solve();
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(numeric_limits<double>::max_digits10);
    solve();
    return 0;
}

void solve() {
    int n;
    cin >> n;
    vector<vector<int>> g(n, vector<int>());
    int u, k;
    REP(i, n) {
        cin >> u >> k;
        u--;
        int v;
        REP(j, k) {
            cin >> v;
            v--;
            g[u].emplace_back(v);
        }
    }

    deque<pair<int, int>> q;
    q.emplace_back(0, 0);

    vector<int> ans(n, -1);
    while (!q.empty()) {
        auto p = q.front(); q.pop_front();
        if (ans[p.first] == -1) ans[p.first] = p.second;

        for (auto r : g[p.first]) {
            if (ans[r] != -1) continue;
            q.emplace_back(r, p.second + 1);
        }
    }
    REP(i, n) cout << i + 1 << " " << ans[i] << endl;
}