Go: package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

const (
	N     = 100
	INFTY = 1 << 21
)

type Graph struct {
	M [N][N]int
	d [N]int
}

func (g *Graph) bfs(s, n int) string {
	var q []int
	q = append(q, s) // push

	for i := 0; i < n; i++ {
		g.d[i] = INFTY
	}
	g.d[s] = 0

	for len(q) != 0 {
		u := q[0]
		q = q[1:] // pop
		for v := 0; v < n; v++ {
			if g.M[u][v] == 0 || g.d[v] != INFTY {
				continue
			}
			g.d[v] = g.d[u] + 1
			q = append(q, v) // push
		}
	}

	var out bytes.Buffer
	for i := 0; i < n; i++ {
		if g.d[i] == INFTY {
			out.WriteString(fmt.Sprintf("%d -1\n", i+1))
			continue
		}
		out.WriteString(fmt.Sprintf("%d %d\n", i+1, g.d[i]))
	}

	return strings.TrimRight(out.String(), "\n")
}

func answer(reader io.Reader) string {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())

	var g Graph
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		u--
		for j := 0; j < k; j++ {
			sc.Scan()
			v, _ := strconv.Atoi(sc.Text())
			v--
			g.M[u][v] = 1
		}
	}

	return g.bfs(0, n)
}

func main() {
	fmt.Println(answer(os.Stdin))
}

C++: #include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

int main(){
    int n; cin >> n;
    Graph G(n);
    for(int i = 0; i < n; i++){
        int u, k; cin >> u >> k;
        for(int j = 0; j < k; j++){
            int a; cin >> a;
            G.at(u - 1).push_back(a);
        }
    }
    vector<int> dist(n, -1);
    dist[0] = 0;
    queue<int> que;
    que.push(1);
    while(!(que.empty())){
        int v = que.front();
        que.pop();
        for(auto nv : G.at(v - 1)){
            if(dist[nv - 1] != -1){
                continue;
            }
            else{
                que.push(nv);
                dist[nv - 1] = dist[v - 1] + 1;
            }
        }
    }
    for(int i = 1; i <= n; i++){
        cout << i << " " << dist[i - 1] << endl;
    }
}

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

using namespace std;

int p[100+10][100+10];
int D[100+10],e[100+10];
int n,a,b,c;

int main(){
	cin >> n;
	for (int i=1; i<=n; i++){
		cin >> a >> b;
		for (int j=1; j<=b; j++){
			cin >> c;
			p[a][c] = 1;
		}
	}
	for (int i=1; i<=n; i++){
		D[i] = -1;
	}
	
	queue<int> Q;
	Q.push(1);
	D[1] = 0;
	e[1] = 1;
	while(!Q.empty()){
		int m = Q.front();
		Q.pop();
		for (int i=1; i<=n; i++){
			if (p[m][i]==1 && e[i]==0){
				D[i] = D[m]+1;
				Q.push(i);
				e[i] = 1;
			}
		}
	}
	
	for (int i=1; i<=n; i++){
		cout << i << ' ' << D[i] << endl;
	}
}

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

const int Max = 100;
int map[Max + 1][Max + 1];

typedef struct{
	bool startflag;
	int distance;
}State;

int main()
{
	int n, k, l, temp;
	std::queue<int> q;
	std::vector<State> state;

	for (int i = 1; i < Max + 1; i++){
		for (int j = 1; j < Max + 1; j++){
			map[i][j] = 0;
		}
	}

	std::cin >> n;
	for (int i = 1; i <= n; i++){
		std::cin >> k >> l;
		for (int j = 1; j <= l; j++){
			std::cin >> temp;
			map[k][temp] = 1;
		}
	}

	State s = { false, 0 };
	for (int i = 0; i <= n; i++){
		state.push_back(s);
	}

	int d = 0;
	while (1){
		if (q.empty() == true){
			bool f = false;
			for (int i = 1; i <= n; i++){
				if (state[i].startflag == false){
					q.push(i);
					state[i].startflag = true;
					d = 0;
					state[i].distance = d;
					d++;
					f = true;
					break;
				}
			}
			if (f == false){
				break;
			}
		}
		int size = q.size();
		for (int j = 0; j < size; j++){
			for (int i = 1; i <= n; i++){
				if (map[q.front()][i] == 1 && state[i].startflag == false){
					q.push(i);
					state[i].startflag = true;
					state[i].distance = d;
				}
			}
			q.pop();
		}
		d++;
	}

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

	return 0;
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include<stack>
#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<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++: #include <iostream>
#include <limits>

using namespace std;

bool adjmatrix[101 * 101];
int costs[101];



void BFS(int vertex, int cur_cost, int N) {
  if (costs[vertex] < cur_cost) return;
  costs[vertex] = cur_cost;
  for (int i =1; i<= N; i++) {
    if(adjmatrix[vertex*101 + i]) {
      BFS(i, cur_cost + 1, N);
    }
  }
}
  

int main() {
  for (int i = 0; i < 101; i++) {
    costs[i] = INT_MAX;
  }
  int N;
  cin >> N;

  for (int i = 0; i < N; i++) {
    int vertex, degree;
    cin >> vertex >> degree;

    for (int j = 0; j < degree; j++) {
      int outvertex;
      cin >> outvertex;
      adjmatrix[vertex * 101 + outvertex] = true;
    }
  }


  /*
  //function to print adjmatrix
  for (int i = 0; i <= N; i++) {
    for (int j= 0; j <= N; j++) {
      if (adjmatrix[i * 101 + j]) {
	cout << "1 ";
      } else {
	cout << "0 ";
      }
    }
    cout << endl;
    }*/

  BFS(1, 0, N);

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

 

}

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

int k[1000][1000], n, a, b, c, t, x[1000];
queue<int>Q;
queue<int>R;

int main() {
	memset(x, -1, sizeof(x));
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> a >> b;
		for (int j = 0; j < b; j++) {
			cin >> c;
			k[i][c] = 1;
		}
	}
	Q.push(1);
	x[1] = 0;
	while (!Q.empty()) {
		t++;
		while (!Q.empty()) {
			for (int i = 1; i <= n; i++) {
				if (x[i] == -1 && k[i][c] == 1) {
					x[i] = t;
					R.push(i);
				}
			}
			Q.pop();
		}
		while (!R.empty()) {
			Q.push(R.front());
			R.pop();
		}
	}
	for (int i = 1; i <= n; i++) {
		cout << i << ' ' << x[i] << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <unordered_map>
#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;
    }
}