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>
#include <utility>
using namespace std;

int main() {
    int N;
    int G[101][101];

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

    int min_dist[101];
    for (int j = 0; j <= N; ++j) min_dist[j] = -1;

    queue<int> que;
    que.push(1); min_dist[1] = 0;
    while (!que.empty()) {
        int v = que.front(); que.pop();

        for (int j = 1; j <= N; ++j) {
            if (G[v][j] && min_dist[j] == -1) {
                min_dist[j] = min_dist[v]+1;
                que.push(j);
            }
        }
    }

    for (int j = 1; j <= N; ++j) {
        cout << j << " " << min_dist[j] << endl;
    }

    return 0;
}

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

using namespace std;
const int INFTY = (1<<21);

int n;
int A[101][101];
int d[101];

void bfs(int s) {
  queue<int> q;
  q.push(s);
  d[s] = 0;

  int u;
  while(!q.empty()) {
    u = q.front(); q.pop();
    for (int v = 0; v < n; ++v) {
      if (A[u][v] == 1 && d[v] == INFTY) {
        d[v] = d[u] + 1;
        q.push(v);
      }
    }
  }
}

int main() {
  
  cin >> n;
  
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < n; ++j) {
      A[i][j] = 0;
    }
  }
  for (int i = 0; i < n; ++i) {
    d[i] = INFTY;
  }

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

  bfs(0);

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

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

using namespace std;
static const int N = 100;
static const int INFTY = (1<<21); // ?????????????????????(2^21)

int n,M[N][N];
int d[N]; // ?????¢??§?¨??????¶???(color)???????????????

void bfs(int s){
	queue<int> q; // ?¨??????????????????????queue????????¨
	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(); // ?????\???????????????u???????????????
		for(int v=0;v<n;v++){
			if(M[u][v] == 0) continue; // ??????u????????????v??????????????????????????°??????
			if(d[v] != INFTY) continue; // ??????v????????§????¨???????????????¨???????????°??????
			d[v] = d[u] + 1; // ??????v????????????u?????°?????????+1?????°??????????????\?????????
			q.push(v); // ?????\????????????v?????\??????
		}
	}
	for(int i=0;i<n;i++){
		cout << i+1 << " " << ((d[i] == INFTY) ? (-1) : d[i]) << endl; // ??????i?????°????????????INFTY??????-1???????????\???????????°????????????????????????
	}
}

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;
		}

C++: #include <iostream>
#include <queue>
using namespace std;
static const int N = 100;
static const int NAV = -1;

int M[N][N];

void bfs(int s, int n, int M[N][N], int d[]) {
    queue<int> Q;
    for (int i = 0; i < n; i++) d[i] = NAV;
    d[s] = 0;
    Q.push(s);

    int u;
    while (!Q.empty()) {
        u = Q.front();
        Q.pop();
        for (int v = 0; v < n; v++) {
            if (M[u][v] != 0 && d[v] == NAV) {
                d[v] = d[u] + 1;
                Q.push(v);
            }
        }
    }
}

int main() {
    int n, 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;
        }
    }

    int d[n];
    bfs(0, n, M, d);

    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]; // ?????¢??§?¨??????¶???(color)???????????????

void bfs(int s) {
  queue<int> q; // ?¨?????????????????????? queue ????????¨
  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, i, j;

  cin >> n;
  for (i = 0; i < n; i++) {
    for (j = 0; j < n; j++) M[i][j] = 0;
  }

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

  bfs(0);

  return 0;
}