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 <bits/stdc++.h>
#define REP(i,n) for (int i = 0; i <(n); ++i)
#define ALL(v) v.begin(), v.end()
using namespace std;

static const int N = 100;
static const int INFTY = (1<<21); //十分に大きな数

int M[N][N];
int n;
int d[N]; //距離で訪問状態　color を管理する

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


  for(int i = 0; i < n; i++) d[i] = INFTY;
  d[s] = 0;

  //sに隣接の値をキューに入れる
  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;

//グラフの初期化
  REP(i,n){
    REP(j,n){
      M[i][j] = 0;
    }
  }

  //行列の作成
  REP(i,n){
    cin >> u >> k;
    u--;
    REP(j,k){
      cin >> v;
      v--;
      M[u][v] = 1;
    }
  }

  bfs(0);

  return 0;

}

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

using namespace std;

const int INF = 100000000;

int main(){
	int n;
	cin >> n;
	vector<vector<int>> node(n+1);
	for(int i=0;i<n;i++){
		int u,k,tmp;
		cin >> u >> k;
		for(int j=0;j<k;j++){
			cin >> tmp;
			node[u].push_back(tmp);
		}
	}
	
	//search
	vector<int> res(n+1,INF);
	queue<int> que;
	queue<int> copied;
	queue<int> zeros;
	que.push(1);
	
	int count = 0;
	for(int i=0;i<n;i++){
		while(que.size()){
			int k = que.front(); que.pop();
			//cout << "-> " << k << endl;
			if(res[k] >= INF) res[k] = count;
			for(int v:node[k]){
				if(res[v] >= INF) copied.push(v);
			}
		}
		count++;
		que = queue<int>(copied);
		copied = queue<int>(zeros);
	}

	//output
	for(int i=1;i<=n;i++){
		if(res[i] >= INF) res[i] = -1;
		cout << i << " " << res[i] << endl;
	}

	return 0;
}

C++: #include <iostream>
#include <queue>
using namespace std;

const int MAX = 100;
int n;
int G[MAX + 1][MAX + 1];
int states[MAX + 1];
int d[MAX + 1];
queue<int> Q;

void bfs(int id) {
  d[id] = 0;
  states[id] = 1;
  Q.push(id);

  while (!Q.empty()) {
    id = Q.front(); Q.pop();
    for (int i = 0; i < n; i++) {
      if (G[id][i] == 1 && states[i] == 0) {
        Q.push(i);
        states[i] = 1;
        d[i] = d[id] + 1;
      }
    }
  }
}

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

  cin >> n;

  int u, v, k;

  for (int i = 0; i < n; i++) {
    d[i] = -1;
    states[i] = 0;
    for (int j = 0; j < n; j++) {
      G[i][j] = 0;
    }
  }

  for (int i = 0; i < n; i++) {
    cin >> u >> k;
    if (k > 0) {
      for (int j = 0; j < k; j++) {
        cin >> v;
        G[u - 1][v - 1] = 1;
      }
    }
  }

  bfs(0);

  for (int i = 0; i < n; i++) {
    cout << i + 1 << " " << d[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 <iostream>
#include <queue>
using namespace std;
const int MAX_N = 100;

int A[MAX_N+1][MAX_N+1];
int D[MAX_N+1];
int N;

void solve() {
  int d;
  queue<int> Q;

  Q.push(1);
  D[1] = d = 0;

  while (!Q.empty()) {
    int c = Q.front(); Q.pop();

    for (int i = 1; i <= N; i++) {
      if (A[c][i] == 1 && D[i] == -1) {
        D[i] = D[c]+1;
        Q.push(i);
      }
    }
  }
}

int main() {
  cin >> N;

  for (int i = 1; i <= N; i++) {
    for (int j = 1; j <= N; j++) {
      A[i][j] = 0;
    }
    D[i] = -1;
  }

  for (int i = 0; i < N; i++) {
    int u, k; cin >> u >> k;
    for (int j = 0; j < k; j++) {
      int t; cin >> t;
      A[u][t] = 1;
    }
  }

  solve();

  for (int i = 1; i <= N; i++) {
    cout << i << ' ' << D[i] << endl;
  }

  return 0;
}

C++: # include <iostream>
# include <vector>
# include <cstdio>
# include <queue>
using namespace std;
struct info
{
	int d = -1;
	bool vis = false;
};
vector<int> a[105];
info *ans;
queue<int> solve;
void bfs()
{
	solve.push(1); 
	ans[1].vis = true; ans[1].d = 0;
	while(!solve.empty())
	{
		int u = solve.front(); solve.pop();
		for(int j = 0;j < a[u].size();j++)
		{
			if(!ans[a[u][j]].vis)
			{
				ans[a[u][j]].vis = true;
				ans[a[u][j]].d = ans[u].d + 1;
				solve.push(a[u][j]);
			}
		}
	}
	
}
int main(void)
{
	int n,cnt,k,u;
	scanf("%d",&n);
	ans = new info [n+1];
	for(int w = 0;w < n;w++)
	{
		scanf("%d %d",&u,&cnt);
		for(int i = 0;i < cnt;i++)
		{
			scanf("%d",&k);
			a[u].push_back(k);
		}
	}
	bfs();
	for(int i = 1;i <= n;i++) printf("%d %d\n",i,ans[i].d);
	return 0;
}