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 <queue>

using namespace std;
const int N = 100;
const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;
const int INFTY = (1<<21);

int n;
int M[N][N] = {0};
int colur[N] = {WHITE};
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,v,i,j,k;
    cin >> n;
    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<bits/stdc++.h>
using namespace std;
#define int long long

const int N = 1000;
vector< vector<int> > G(N);
int d[N],visited[N];

void bfs(){

  fill(d+2,d+N,N);
  queue<pair<int,int>> q;
  q.push({1,1});
  while(!q.empty()){
    auto p = q.front(); q.pop();
    int s = p.first;
    int cnt = p.second;
    for(int i = 0; i < G[s].size(); i++){
      int v = G[s][i];
      d[v] = min(d[v],cnt);
      if(!visited[v]) q.push({v,cnt+1});
      visited[v] = 1;
    }
  }
}

signed main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

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

  bfs();
  for(int i = 1; i <= n; i++){
    if(d[i] != N) cout << i << " " << d[i] << endl;
    else cout << i << " " << -1 << endl;
  }

  return 0;
}

C++: #include <stdio.h>
#define MAX 101

int A[MAX][MAX], s[MAX], h[MAX];

void serch(int x, int y){
  int i;
  h[x] = y;
  for(i=1; i<=s[x]; i++){
    if(h[A[x][i]] > y)
      serch(A[x][i], y+1);
  }
}

int main(){
  int i, j, k, n;
  
  scanf("%d", &n);
  for(i=1; i<=n; i++){
    h[i] = 10000;
    for(j=1; j<=n; j++)
      A[i][j] = 0;
  }
  
  for(i=1; i<=n; i++){
    scanf("%d", &k);
    scanf("%d", &s[k]);
    for(j=1; j<=s[k]; j++)
      scanf("%d", &A[k][j]);
  }
  
  serch(1,0);
  
  for(i=1; i<=n; i++){
    if(h[i] == 10000)
      h[i] = -1;
    printf("%d %d\n", i, h[i]);
  }
  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(void) {
  int u, k, v;
  cin >> n;
  //init
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < n; j++) {
      M[i][j] = 0;
    }
  }


  //??£??\???????????¨??????0-origin?????£??\???????????????
  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<iostream>
#include<queue>
using namespace std;
#define MAX 100
#define INFTY 1 << 21

int n, M[MAX][MAX];
int dist[MAX];

void bfs_visit(int u){
    queue<int> q;
    q.push(u);
    int v;
    for(v = 0; v < n; v++) dist[v] = INFTY;
    dist[u] = 0;

    while(!q.empty()){
        u = q.front();
        q.pop();
        for(v = 0;  v < n; v++){
            if(M[u][v] == 0) continue;
            if(dist[v] != INFTY) continue;
            dist[v] = dist[u] + 1;
            q.push(v);
        }

    }
    for(int i = 0; i < n; i++){
            cout << i + 1 << " " << (dist[i] == INFTY ? -1 : dist[i]) << endl;
    }
}

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

    bfs_visit(0);

    return 0;
}

C++: #include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<cmath>
#include<stdio.h>
#include<queue>
#include <climits>
#include <map>
#include <set>
const int mod = 1e9 + 7;
const long long INF = 1LL << 60;
using namespace std;
typedef long long ll;
 
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 <cstdio>
#include <queue>
using namespace std;

int dt[101][101];
int d[101];

int n;
int t=0;
void bfs(int s){
	priority_queue<int, vector<int>, greater<int> > que;
	for(int i=1;i<=n;i++)
		d[i]=-1;
	d[s]=0;
	que.push(s);
	while(!que.empty()){
		int nxt=que.top();que.pop();
		for(int i=1;i<=n;i++){
			if(dt[nxt][i]&&d[i]==-1){
				que.push(i);
				d[i]=d[nxt]+1;
			}
		}
	}
}
int main(){
	int fi, v, g;
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		scanf("%d %d",&fi,&v);
		for(int j=1;j<=v;j++){
			scanf("%d",&g);
			dt[fi][g]=1;
		}
	}
	d[1]=0;
	bfs(1);
	for(int i=1;i<=n;i++){
		if(!d[i]){
			bfs(i);
		}
	}
			
	for(int i=1;i<=n;i++){
		printf("%d %d\n",i,d[i]);
	}
	return 0;
}