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 <unordered_map>
#include <set>
#include <queue>
//#include "../cxx-prettyprint/prettyprint.hpp"


int main() {
    int n;
    std::cin >> n;

    std::unordered_map<int, std::vector<int>> Adj(n);

    for (int i = 0; i < n; i ++) {
        int u, k;
        std::cin >> u >> k;
        std::vector<int> V(k);
        for (int& v : V) {
            std::cin >> v;
        }
        Adj[u] = V;
    }

    std::set<int> nodes_unvisited;
    std::unordered_map<int, int> distances;

    for (int i = 1; i <= n; i ++) {
        nodes_unvisited.insert(i);
    }

    nodes_unvisited.erase(1);
    distances[1] = 0;
    std::queue<int> queue;
    queue.push(1);

    while (!queue.empty()) {
        int u = queue.front();
        queue.pop();
        for (int v : Adj[u]) {
            if (nodes_unvisited.find(v) != nodes_unvisited.end()) {
                nodes_unvisited.erase(v);
                distances[v] = distances[u] + 1;
                queue.push(v);
            }
        }
    }

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

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

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

int M[N+1][N+1];  // 隣接行列

void bfs(int n, int d[], int color[]) {
  int vertex;
  queue<int> Q;
  
  // 初期状態
  for (int i = 1; i <= n; i++) {
    d[i] = -1;
    color[i] = WHITE;
  }
  vertex = 1;  // 始点
  d[vertex] = 0;
  Q.push(vertex);
  //bfs
  while (!Q.empty()) {
    vertex = Q.front();
    Q.pop();
    color[vertex] = GRAY;
    // 見訪問の隣接する頂点を探してキューに入れる
    for (int i = 1; i <= n; i++) {
      if (M[vertex][i] && color[i] == WHITE) {
        color[i] = GRAY;
        Q.push(i);
        d[i] = d[vertex] + 1;  // 距離
      }
    }
    color[vertex] = BLACK;  // 処理終了
  }
}

int main() {
  int i, j, n, u, k, v, d[N+1], color[N+1];

  cin >> n;
  // 与えられた隣接リストを隣接行列表現に直す
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= n; j++) {
      M[i][j] = 0;
    }
  }
  for (i = 0; i < n; i++) {
    cin >> u >> k;
    for (j = 0; j < k; j++) {
      cin >> v;
      M[u][v] = 1;
    }
  }
      
  // bfs
  bfs(n, d, color);

  // 出力
  for (i = 1; i <= n; i++) cout << i << " " << d[i] << endl;

  return 0;
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>
 
#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
 
using namespace std;
 
typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;
 
const int INF=1<<29;
const double EPS=1e-9;
 
const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};

std::vector<vector<int> > G;
std::vector<int> flag;
std::vector<int> in;
int N;
typedef pii P;

int main(int argc, char const *argv[]) {
	
	cin >> N;

	for (int i = 0; i < N; ++i) {
		G.push_back(vector<int>());
		flag.push_back(0);
		in.push_back(-1);
		for (int j = 0; j < N; ++j) {
			G[i].push_back(0);
		}
	}

	for (int i = 0; i < N; ++i) {
		int u, k;
		cin >> u >> k;
		u--;
		for (int j = 0; j < k; ++j) {
			int v;
			cin >> v;
			v--;
			G[u][v] = 1;
		}
	}
	queue<P> q;
	q.push(mp(0, 0));
	while(!q.empty()) {
		P u = q.front(); q.pop();
		int dist = u.second;
		in[u.first] = dist;
		flag[u.first] = 1;
		for (int i = 0; i < N; ++i) {
			if (flag[i] == 0 && G[u.first][i] == 1) {
				q.push(mp(i, dist + 1));
			}
		}
	}

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

	return 0;
}

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

using namespace std;

#define ll long long
typedef complex<double> P;

int main() {
  int n; cin >> n;
  int adj[n][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;
      adj[u-1][v-1] = 1;
    }
  }

  int d[n];
  fill(d, d+n, -1);

  queue<int> que;
  que.push(0);
  d[0] = 0;

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

    for (int i = 0; i < n; i++) {
      if(adj[v][i] == 1 && d[i] == -1) {
        que.push(i);
        d[i] = d[v] + 1;
      }
    }

  }

  for (int i = 0; i < n; i++) {
    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);
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,k,v;
  cin>>n;
  for(int i=0;i<n;i++){
    for(int j=0;j<k;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;
}