Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

func stringifyArray(arr []int) string {
	return strings.TrimRight(fmt.Sprintf("%+v", arr)[1:], "]")
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, &g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

func fillDistancesByBreadthFirstSearch(g *DirectedGraph, startNode *DirectedGraphNode) {
	startNode.visited = true
	startNode.d = 0

	queue := Queue{}
	queue.enqueue(startNode)
	for !queue.isEmpty() {
		u := queue.dequeue().node
		for _, adjacent := range u.adjacents {
			if !adjacent.visited {
				adjacent.visited = true
				adjacent.d = u.d + 1
				adjacent.parent = u
				queue.enqueue(adjacent)
			}
		}
		u.visited = true
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	// fmt.Println(g)
	fillDistancesByBreadthFirstSearch(g, &g.nodes[1])
	// fmt.Println(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		distance := node.d
		if distance == infty {
			distance = -1
		}
		fmt.Println(node.key, distance)
	}
}

C++: #include <iostream>
#include <string>
#include <map>
#include <queue>
#include <algorithm>
using namespace std;
#define MAX 100000

static const int N =100;
static const int INFTY =(1<<21);

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]==1){
        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>
//#define int long long
//#define _DEBUG
#include <queue>
#include <vector>
using namespace std;
int N, T[107][107], D[107]; //T[i][j]:i->T[i][j]の辺
int const infty = -1, none = -9;
queue<int> Q;
void solve(){
    Q.push(0);
    D[0] = 0;
    while(true){
#ifdef _DEBUG
        cout << "Q1 ";
        int length = Q.size();
        for(int k=0; k<length; k++){
            int qf = Q.front(); Q.pop();
            cout << qf << " ";
            Q.push(qf);
        }cout << endl; 
#endif
        int top = Q.front(); Q.pop();
#ifdef _DEBUG
        cout << "top " << top << endl << "Q2 ";
        length = Q.size();
        for(int k=0; k<length; k++){
            int qf = Q.front(); Q.pop();
            cout << qf << " ";
            Q.push(qf);
        }cout << endl; 
#endif
        for(int j=0; j<N; j++){
#ifdef _DEBUG
            cout << j << ", " << T[top][j] << endl;
            cout << "top " << top << endl << "Q3 ";
            length = Q.size();
            for(int k=0; k<length; k++){
                int qf = Q.front(); Q.pop();
                cout << qf << " ";
                Q.push(qf);
            }cout << endl; 
#endif
            if(T[top][j] == none)break;
            if(D[ T[top][j] ] != infty)continue;
            Q.push( T[top][j] );
            D[ T[top][j] ] = D[top]+1;
        }
#ifdef _DEBUG
        cout << "D " ;
        for(int k=0; k<N; k++) cout <<D[k]<<" ";
        cout << endl;
#endif
        if(Q.empty()) break;
    }
}
void get(){
    cin >> N;
    for(int i=0; i<N; i++){
        D[i] = infty;
        for(int j=0; j<N; j++){
            T[i][j] = none;
        }
    }
    for(int i=0; i<N; i++){
        int i_, k;
        cin >> i_ >> k;
        for(int j=0; j<k; j++){
            int vj;
            cin >> vj;
            T[i][j] = vj-1;
        }
    }
}

signed main(){
    get();
    
#ifdef _DEBUG
    for(int k=0; k<N; k++) cout << D[k] << " ";
    cout << endl;
    for(int k=0; k<N; k++){
        for(int l=0; l<N; l++){
            if(T[k][l] == none)break;
            cout << T[k][l] << " ";
        }
        cout << endl;
    }
#endif
    solve();
    for(int i=0; i<N; i++){
        cout << i+1 << " " << D[i] << endl;
    }
}

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] <<" ";
  //     }
  //    }
  // }


}