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<queue>

using namespace std;

const static int N=100;
const static 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[u]!=0){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,k;
    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; k++){
            cin>>v;
            v--;
            M[u][v]=1;
        }
    }
    bfs(0);
    return 0;
}

C++: #include<iostream>
#include<queue>
#include<vector>
using namespace std;
int main(){
  queue<int> q;
  int n,a,k,u,c[101];
  vector<int>  d[101];
  cin>>n;for(int i=0;i<n;i++){
    cin>>u>>k;c[i]=-1;
    d[u].resize(k);
    for(int j=0;j<k;j++) cin>>d[u][j];
  }q.push(1),c[1]=0;
  while(!q.empty()){
   a=q.front(),q.pop();
    for(int i=0;i<d[a].size();i++)
      if( d[a][i]>1 && c[d[a][i]]==-1) q.push(d[a][i]),c[d[a][i]]=c[a]+1;
  } for(int i=1;i<=n;i++) cout<<i<<" "<<c[i]<<endl;
  return 0;
}

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

#define MAX 100
#define WHITE 0
#define GRAY 1
#define BLACK 2

#define NO -1

using namespace std;


int adjacencyList[MAX + 1][MAX + 1];
int color[MAX + 1];
int d[MAX + 1];
int n;



void bfs(int o)
{
	queue<int> S;
	S.push(o);
	color[o] = GRAY;
	d[o] = 0;

	int fr;

	while (S.size() > 0) {
		fr = S.front();
		S.pop();
		color[fr] = BLACK;
		for (int i = 1; i <= n; i++) {
			if (color[i] == WHITE && adjacencyList[fr][i] != NO) {
				S.push(i);
				color[i] = GRAY;
				d[i] = d[fr] + 1;
			}
		}
	}

}

int main(void)
{

	int u;
	int k;
	int v;


	cin >> n;

	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			adjacencyList[i][j] = NO;
		}
	}

	for (int i = 0; i < n; i++) {
		cin >> u >> k;

		for (int j = 0; j < k; j++) {
			cin >> v;
			adjacencyList[u][v] = 1;
		}

	}

	bfs(1);

	for (int i = 1; i <= n; i++) {
		cout << i <<  " " <<d[i] << endl;
	}


	return 0;
}

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

#define INFTY (1 << 30)

void BFS(bool mT[][100], int firstVerVal, int verNum, int distance[]) {
	queue<int>  verQ;
	verQ.push(firstVerVal);
	for (int i = 0; i < verNum; i++)
		distance[i] = INFTY;
	distance[firstVerVal] = 0;

	while (!verQ.empty()) {
		int curVerVal = verQ.front();
		verQ.pop();
		for (int i = 0; i < verNum; i++) {
			if (!mT[curVerVal][i] || distance[i] != INFTY) continue;
			distance[i] = distance[curVerVal] + 1;
			verQ.push(i);
		}
	}
}

int main() {
	bool matrixTable[100][100];
	int distance[100];
	int verNum;
	cin >> verNum;

	for (int i = 0; i < verNum; i++)
		for (int j = 0; j < verNum; j++)
			matrixTable[i][j] = false;
		
	for (int i = 0; i < verNum; i++) {
		int anyVerVal, anyVerNum;
		cin >> anyVerVal >> anyVerNum;
		for (int j = 0; j < anyVerNum; j++) {
			int verValue; cin >> verValue;
			matrixTable[anyVerVal - 1][verValue - 1] = true;
		}
	}

	BFS(matrixTable, 0, verNum, distance);

	for (int i = 0; i < verNum; i++) {
		cout << i + 1 << " ";
		if (distance[i] == INFTY)
			cout << -1 << endl;
		else
			cout << distance[i] << endl;
	}

	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<cassert>
#include<cstdio>
#include<queue>
 
using namespace std;
 
int N, G[100][100], V[100], D[100];//G:２頂点,V:次数,D:距離
 
void bfs(int src){
    queue<int> Q;
    Q.push(src);
    fill(D, D + N, -1);
    D[src] = 0;
    while (! Q.empty()){
        int cur = Q.front();
        Q.pop();
        cerr << cur+1 << " " << D[cur] << endl;
        for (int k = 0; k < N; k++){
            if (G[cur][k] == 1 && D[k] == -1){
                D[k] = D[cur]+1;
                Q.push(k);
            }
        }
    }
}
 
int main(){
    scanf("%d", &N);
        int id, c;
        for (int i = 0; i < N; i++){
            scanf("%d", &id); id--;//配列は0から始まるので、頂点番号を-1して考える。
            scanf("%d", V + id);
            for (int j = 0; j < V[id]; j++){
                scanf("%d", &c); c--;//配列は0から始まるので、頂点番号を-1して考える。
                G[id][c] = 1;
            }
        }//データの読み込み完了。
    bfs(0);
}