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 <vector>
#include <algorithm>
#include <queue>
#include <utility>

std::queue<std::pair<int, int>> q;
std::vector<std::vector<int>> vec;
std::vector<int> distances;
int n, id, num, d;

void bfs_search(int start_id) {
    q.push(std::make_pair(start_id, 0));
    while (!q.empty()) {
        auto x = q.front();
        q.pop();
        distances[x.first-1] = x.second;
        for (int i = 1; i <= n; i++) {
            if (vec[x.first][i] == 1 && distances[i-1] == -1) {
                q.push(std::make_pair(i, x.second+1));
                distances[i-1] = x.second;
            }
        }
    }
}

int main() {
    std::cin >> n;
    vec.assign(n+1, std::vector<int>(n+1, -1));
    for (int i = 0; i < n; ++i) {
        std::cin >> id >> num;
        for (int p = 0; p < num; p++) {
            std::cin >> d;
            vec[id][d] = 1;
        }
    }
    for (int i = 0; i < n; i++) {
        distances.push_back(-1);
    }
    bfs_search(1);
    for (int i = 0; i < n; i++) {
        std::cout << i+1 << " " << distances[i] << std::endl;
    }
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <algorithm>

using namespace std;

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

static const int N = 100;
static const int FAR = (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] = FAR;
	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] != FAR) continue;
			d[v] = d[u] + 1;
			q.push(v);
		}
	}
	for (int i = 0; i < n; ++i)
		cout << i + 1 << " " << ((d[i] == FAR) ? -1 : d[i]) << endl;
}

int main(){
	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) {
		int u, d, v; cin >> u >> d;
		for (int j = 0; j < d; ++j) {
			cin >> v;
			M[u - 1][v - 1] = 1;
		}
	}

	bfs(0);

	return 0;
}

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

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

int main()
{   
    /* 座席　（中央×後）*/
    //資料の説明通りにやってみたつもりです

    int n;
    cin >> n;
    vector<vector<int>> edges(n, vector<int>());

    REP(i, n) {
        int u, k, e;
        cin >> u >> k;

        REP(j, k) {
            cin >> e;
            edges.at(u-1).push_back(e-1);
        }
    }

    queue<int> Q;
    vector<int> dst(n, 1000000);

    dst[0] = 0;
    Q.push(0);

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

        REP(i, edges[cur].size()) {
            if (dst[edges[cur][i]] == 1000000)
                Q.push(edges[cur][i]);
                if (dst[edges[cur][i]] > dst[cur]+1)
                    dst[edges[cur][i]] = dst[cur]+1;
        }
    }

    REP(i, n) {
        if (dst[i] == 1000000)
            cout << i+1 << " " << -1 << endl;
        else 
            cout << i+1 << " " << dst[i] << endl;
    }
}

C++: #include <iostream>
#include <queue>
#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 2
using namespace std;
int m[N][N],color[N],d[N],n;



void bfs(int s){
	
	queue<int> q;
	q.push(s);
	for(int i=0;i<N;i++){
		color[i] = WHITE;
		d[i] = (1<<21);
	}
	d[s] = 0;
	color[s] = GRAY;
	int u;
	while(!q.empty()){
		u = q.front();
		q.pop();
		
		for(int v=0;v<n;v++){
			if(m[u][v]&&color[v]==WHITE){
				color[v] = GRAY;
				d[v] = d[u]+1;
				q.push(v);
			}
		}
	}
	for(int i=0;i<n;i++){
			cout<<i+1<<" "<<((d[i]==(1<<21))?(-1):(d[i]))<<endl; 
		}
}
	
	int main(){
		int u,v,k;
		
		cin>>n;
		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 <set>
#include <map>
#include <list>
#include <queue>
#include <stack>
#include <cmath>
#include <ctype.h>
#include <ctime>
#include <cstdio>
#include <vector>
#include <string>
#include <bitset>
#include <cctype>
#include <cstdlib>
#include <cstring>
#include <utility>
#include <numeric>
#include <complex>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <iostream>
#include <iterator>
#include <algorithm>

using namespace std;
#define N 100
#define INF 1e9

queue<int> Q;
int n,M[N][N];
int dist[N];

void bsf(int l){
	Q.push(l);
	for(int i = 0;i < n;i++) dist[i] = INF;

	dist[l]=0;
	while(!Q.empty()){
		int u = Q.front();
		Q.pop();
		for(int i=0;i<n;i++){
			if(M[u][i] == 0)continue;
			if(dist[i] != INF)continue;
			dist[i] = dist[u] + 1;
			Q.push(i);
		}
	}
}

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;
		}
	}
	bsf(0);
	return 0;
}