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>

using namespace std;

#define N_MAX 100

int Adj[N_MAX][N_MAX] = {};
int Min_d[N_MAX];

void bfs(int v, int d, int num_node);

int main()
{
    int n, i, u, k, v, j;

    cin >> n;

    for (i = 0; i < n; i++) Min_d[i] = -1;

    //??£??\???????????????
    for (i = 0; i < n; i++) {
        cin >> u >> k;
        while (k-- > 0) {
            cin >> v;
            Adj[u-1][v-1] = 1;
        }
    }
/*
    cout << "show Adjacency matrix" << endl;
    for (i = 0; i < n; i++) {
        for (j = 0; j < n ; j++) {
            if (j == n - 1)
                cout << Adj[i][j] << endl;
            else
                cout << Adj[i][j] << ' ';
        }
    }
*/
    //??¢?´¢??????
    Min_d[0] = 0;
    bfs(1, 1, n);

    //????????????
    for(i = 1; i <= n; i++) {
        cout << i << ' ' << Min_d[i-1] << endl;
    }

    return 0;
}

void bfs(int v, int d, int num_node) {
    int i;
//    cout << "bfs node : " << v << endl;

    for(i = 1; i <= num_node; i++) {
        if (Adj[v-1][i-1] == 1) {
            if (Min_d[i-1] == -1 || Min_d[i-1] > d) {
                Min_d[i-1] = d;
                bfs(i, d+1, num_node);
            }
        }
    }
}

C++: #include <iostream>
#include <vector>
#include <queue>
using namespace std;
vector<int> G[110], d(110);

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

    for (int i = 0; i < n; i++) d[i] = -1;

    queue<int> que;
    que.push(0);
    d[0] = 0;
    while (!que.empty()) {
        int u = que.front(); que.pop();
        for (int v: G[u]) {
            if (d[v] == -1) {
                que.push(v);
                d[v] = d[u] + 1;
            }
        }
    }

    for (int i = 0; i < n; i++) {
        cout << i+1 << " " << d[i] << endl;
    }
}

C++: #include <bits/stdc++.h>
typedef long long ll;
typedef unsigned long long ull;
#define reps(i,s,n) for(int (i)=(s);(i)<(n);++(i))
#define rep(i,n) reps(i,0,n)
#define reptr(i,n) for(int (i)=(n);(i)>=0;--(i))
#define All(x) (x).begin(),(x).end()
const ll MOD=1e9+7;
using namespace std;

vector<int> ans;
int state[105][105]={};
int n;
void bfs(int s){
  queue<int> q;
  q.push(s);
  while(!q.empty()){
    int u=q.front();
    q.pop();
    for(int v=0;v<n;v++){
      //隣接していない
      if(state[u][v]==false) continue;
      //既に探索されている
      if(ans[v]!=INT_MAX) continue;
      //未探索の場合
      ans[v] = ans[u]+1;
      q.push(v);
    }
  }

  rep(i,n){
    if(ans[i]==INT_MAX) ans[i] = -1;
    cout << i+1 << " " << ans[i] << endl;
  }
}

int main(){
  cin >> n;
  ans.resize(n,INT_MAX);
  ans[0]=0;
  rep(i,n){
    int u,k;
    cin >> u >> k;
    u--;
    rep(j,k){
      int v;
      cin >> v;
      v--;
      state[u][v]=1;
    }
  }
  bfs(0);
}

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

int n;

int V[100][100];
int D[100];
int d = 0;

std::queue<int> Q;

void bfs(int r) {
    Q.push(r);
    D[r] = 0;
    while (Q.size()) {
        r = Q.front();
        Q.pop();
        for (int i = 0; i < n; i++) {
            if ((D[i] == 0) && (V[r][i] == 1)) {
                Q.push(i);
                D[i] = D[r] + 1;
            }
        }
    }
}


int main() {
    std::cin >> n;
    for (int i = 0; i < n; i++) {
        int id, e_num;
        std::cin >> id >> e_num;
        for (int j = 0; j < e_num; j++) {
            int t;
            std::cin >> t;
            V[id - 1][t - 1] = 1;
        }
    }

    bfs(0);
    for (int i = 0; i < n; i++) {
        std::cout << i + 1 << " " << D[i] << std::endl;
    }
}

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

using namespace std;
using Graph = vector<vector<int>>;

int main() {

    int n; cin >> n;
    int u, k;

    Graph G(n+1);
    for ( int i = 1; i <= n; ++i ) {
        cin >> u >> k;
        for ( int j = 1; j <= k; ++j ) {
            int a;
            cin >> a;
            G[i].push_back(a);
            //G[b].push_back(a);
        }
    }

    /*for ( int i = 1; i <= n; ++i ) {
        for ( int ax : G[i] ) {
            cout << ax ;
        }
        cout << endl;
    }*/

    vector<int> dist(n+1,-1);
    queue<int> que;

    dist[1] = 0;
    que.push(1);

    while ( !que.empty() ) {
        int v = que.front();
        que.pop();

        for ( int nv : G[v] ) {
            if ( dist[nv] != -1 ) continue;
            dist[nv] = dist[v] + 1;
            que.push(nv);
        }
    }

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