Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

type AdjacentList struct {
	matrix [][]int
}

func NewEmptyAdjacentList(dim int) *AdjacentList {
	matrix := make([][]int, dim)
	for i := 0; i < dim; i++ {
		matrix[i] = make([]int, dim)
	}
	return &AdjacentList{matrix: matrix}
}

func (al *AdjacentList) set(node int, adjacent int) {
	al.matrix[node-1][adjacent-1] = 1
}

func (al *AdjacentList) findAdjacentsFor(node int) []int {
	adjacents := []int{}
	for i, v := range al.matrix[node-1] {
		if v == 1 {
			adjacents = append(adjacents, i+1)
		}
	}
	return adjacents
}

type DistanceList struct {
	list []int
}

func NewDistanceList(dim int) *DistanceList {
	list := make([]int, dim)
	for i := 0; i < dim; i++ {
		list[i] = -1
	}
	return &DistanceList{list: list}
}

func (dl *DistanceList) set(node int, distance int) {
	dl.list[node-1] = distance
}

func (dl *DistanceList) get(node int) int {
	return dl.list[node-1]
}

func (dl *DistanceList) isVisited(node int) bool {
	return dl.list[node-1] >= 0
}

type Position struct {
	node     int
	distance int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	dim, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	al := NewEmptyAdjacentList(dim)

	for i := 1; i <= dim; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}

		adjacentNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		for j := 0; j < adjacentNum; j++ {
			adjacent, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			al.set(node, adjacent)
		}
	}

	dl := NewDistanceList(dim)

	bfs(al, dl)

	for i := 1; i <= dim; i++ {
		fmt.Printf("%d %d\n", i, dl.get(i))
	}
}

func bfs(al *AdjacentList, dl *DistanceList) {
	stack := []Position{Position{node: 1, distance: 0}}
	for len(stack) > 0 {
		currentPosition := stack[0]
		stack = stack[1:]
		if !dl.isVisited(currentPosition.node) {
			dl.set(currentPosition.node, currentPosition.distance)
		}
		for _, v := range al.findAdjacentsFor(currentPosition.node) {
			stack = append(stack, Position{node: v, distance: currentPosition.distance + 1})
		}
	}
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

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

struct node {
	std::vector<int> child;
	int distance;
};

int main() {
	int node_num;

	std::cin >> node_num;

	std::vector<node> n(node_num);

	for (int i = 0; i < node_num; i++) {
		int num, to, node_val;
		std::cin >> node_val >> num;
		for (int j = 0; j < num; j++) {
			std::cin >> to;
			n[node_val - 1].child.push_back(to);
		}
		n[i].distance = -1;
	}

	//???????????????????????¢0
	n[0].distance = 0;
	std::queue<int> q;
	int dist = 1;
	q.push(1);
	while(q.size() != 0){
		int num = q.front();
		q.pop();
		for (std::vector<int>::iterator it = n[num - 1].child.begin(); it != n[num - 1].child.end(); it++) {
			q.push(*it);
			if (n[*it - 1].distance > dist || n[*it - 1].distance == -1) {
				n[*it - 1].distance = dist;
			}
		}
		dist++;
	}

	for (int i = 0; i < node_num; i++) {
		std::cout << i + 1 << " " << n[i].distance << std::endl;
	}
	return 0;
}

C++: #include<iostream>
#include<queue>
static const int N = 100;
static const int INFTY = (1 << 21);
using namespace std;

int n, M[N][N],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[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++: //
// Created by ?????°?????? on 2016/05/15.
//

#include <iostream>
#include <queue>
using namespace std;
const int N = 100;
const 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[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,v,k;
    for (int i = 0; i < n ; ++i) {
        for (int j = 0; j < n ; ++j) {
            M[i][j] = 0;
        }
    }
    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 <bits/stdc++.h>
using namespace std;
#define inf 1<<30

int n,M[105][105],d[105];
queue<int> Q;

void dfs(int s){
	d[s]=0;
	Q.push(s);
	int v;
	while(!Q.empty()){
		s=Q.front();Q.pop();
		for(int v=0;v<n;v++){
			if(M[s][v]==0){
				continue;
			}
			if(d[v]!=-1){
				continue;
			}
			d[v]=d[s]+1;
			Q.push(v);
		}
	}
}

int main() {
  cin>>n;
  for(int i=0;i<105;i++){
  	d[i]=-1;
    for(int j=0;j<105;j++){
      M[i][j];
    }
  }
  int u,k,v;
  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;
    }
  }
  dfs(0);
  for(int i=0;i<n;i++){
  	printf("%d %d\n",i+1,d[i]);
  }
}

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

#define N 100
#define 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[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() {
  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 a, b;
    cin >> a >> b;
    --a;
    for ( int j = 0; j < b; j++ ) {
      int c;
      cin >> c;
      M[a][--c] = 1;
    }
  }

  bfs(0);

  return 0;
}

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;
    }
}