Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	nodes := make([]Node, n)

	for i := 0; i < n; i++ {
		nodes[i].list = make([]int, 0)
		nodes[i].d = -1
	}

	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		u--
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			v--
			nodes[u].list = append(nodes[u].list, v)
		}
	}

	queue := make([]int, n)
	queue[0] = 0
	nodes[0].d = 0
	d := 0
	i, j := 0, 1
	for i < j {
		d++
		prev := j
		for i < prev {
			for k, l := 0, len(nodes[queue[i]].list); k < l && i < n; k++ {
				if nodes[nodes[queue[i]].list[k]].d != -1 {
					continue
				}
				nodes[nodes[queue[i]].list[k]].d = d
				queue[j] = nodes[queue[i]].list[k]
				j++
			}
			i++
		}
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i+1, nodes[i].d))
	}

	writer.Flush()
}

// Node ...
type Node struct {
	list []int
	d    int
}

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

using namespace std;

int D[100100];//始点からの距離を入れる

int g[1001][1001]={{0}};//要素を0で初期化
void bfs(int src,int n){//srcは開始位置この場合だと頂点1だから0
  // cerr << "bfs_root = " << src << endl;
  queue<int> Q;
  Q.push(src);
  D[src] = 0;
  while (! Q.empty()  ){
    int cur = Q.front();
    Q.pop();
    // cerr << "visiting_" << cur << " " <<D[cur] <<endl;
    for(int dst= 0; dst < n; dst++){
      if(g[cur][dst]==1 && D[dst]==0){
        D[dst]=D[cur]+1;
        Q.push(dst);
      }
    }
  }
}
void ans(int n){
  cout << 1 <<" "<< 0 <<enl;
  for (int i = 1; i < n; ++i)
  {
    if(D[i]==0){
      cout << i+1 << " "<< -1 <<endl;
    }else{
      cout << i+1 <<" "<< D[i]<<endl;
    }
  }

}

int main(){
  // int g[1001][1001]={{0}};//要素を0で初期化
  int n,a,b,c;
  cin >> n;
  for (int i = 0; i < n; ++i)
  {
    cin >> a >> b ;
    for (int i = 0; i < b; ++i)
    {
      cin >> c;
      g[a-1][c-1]=1;/* code */
    }
  }
  bfs(0,n);
  ans(n);
  // for (int i = 0; i < n; ++i)
  // {
  //    for (int j = 0; j < n; ++j)
  //    {
  //     if (j==n-1)
  //     {
  //       cout << g[i][j] << endl;
  //     }else{
  //       cout << g[i][j] <<" ";
  //     }
  //    }
  // }


}

C++: #include <algorithm>
#include <bitset>
#include <cctype>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;

int main() {
    int n;
    cin >> n;
    vector<vector<int>> edges(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--;
            edges[u].push_back(v);
        }
    }

    vector<int> ds(n, -1);
    ds[0] = 0;
    queue<pair<int, int>> q;
    q.push(make_pair(0, 0));
    while (!q.empty()) {
        int u = q.front().first;
        int d = q.front().second;
        q.pop();
        if (ds[u] > 0) {
            continue;
        }
        ds[u] = d;
        for (auto v : edges[u]) {
            q.push(make_pair(v, d + 1));
        }
    }

    for (int i = 0; i < n; i++) {
        cout << i + 1 << " " << ds[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 <stdio.h>
#include <vector>
#include <queue>

using namespace std;
int ans[100][100] = {};
int now = 0, n;

int main() {
    int u, k, tmp;
    cin >> n;
    vector<int> dist(n, -1);
    queue<int> que;
    for (int i = 0; i < n; i++) {
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            cin >> tmp;
            ans[u - 1][tmp - 1] = 1;
        }
    }
/*
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; ++j) {
            cout << ans[i][j] << " ";
        }
        cout << endl;
    }
*/
    dist[0] = 0;
    que.push(0);
    while (!que.empty()) {
        int v = que.front();
        //cout << v;
        que.pop();

        for (int i = 0; i < n; ++i) {
            int nv = ans[v][i];
            if (dist[i] == -1 and nv != 0) {
                dist[i] = dist[v] + 1;
                que.push(i);
            }
        }
        //cout << endl;
    }
    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];  // 距離で訪問状態（color）を管理する

void bfs(int s) {
  queue<int> q;  // 標準ライブラリの queue を使用
  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<bits/stdc++.h>
using namespace std;
int vis[111],G[111][111],cn,n,d[111];
int  bfs(int i){
  	queue<int>q;
  	q.push(i);
  	vis[i]=1;
	while(!q.empty()){
		int temp=q.front();
		vis[temp]=1;
		q.pop();
		for(int j=1;j<=n;j++){
			if(vis[j]==0&&G[temp][j]!=0){
				d[j]=d[temp]+1;
				vis[j]=1;
				q.push(j);
			}
		}
	}  
}

int main(){
    scanf("%d",&n);
	for(int i=1;i<=n;i++){	
	int v2,v1,k;
		scanf("%d%d",&v1,&k);
		for(int j=0;j<k;j++){
			scanf("%d",&v2);
			G[v1][v2]=1;
		}
}
    bfs(1);
    for(int i=1;i<=n;i++) {
    	if(i==1)
    	printf("%d %d\n",i,d[i]);
    	else if(d[i]==0){
    			printf("%d %d\n",i,-1);
		} 
		else printf("%d %d\n",i,d[i]);
	}
	 
	 return 0;
}

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

#define REP(i,n) for(int i=0;i<n;i++)

using namespace std;


int main()
{
	int n;
	cin>>n;
	
	bool adj[n+10][n+10]={};
	
	for(int i=1;i<n+1;++i){//1index
		
		int u;
		int k;
		cin>>u>>k;
		
		for(int j=1;j<k+1;++j){//1index
			int v;
			cin>>v;
			adj[i][v]=true;
		}
	}
	
	int d[n+10];
	for(int i=1;i<n+1;++i){
		d[i]=-1;
	}
	
	d[1]=0;
	
	queue<int> que;
	que.push(1);
	while(!que.empty()){
		int now=que.front();
		que.pop();
		
		int a=d[now];
		
		for(int j=1;j<n+1;++j){
			
			if((adj[now][j]) and (d[j]==-1)){
				d[j]=a+1;
			que.push(j);
			
			}
			
		}
	}
	
	for(int i=1;i<n+1;++i){
		cout<<i<<" "<<d[i]<<endl;
	}
	
}