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 <cstdlib>
#include <string>
#include <typeinfo>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <stack>
#include <queue>
using namespace std;
static const int N = 100;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;
static const int INFTY = (1<<21);
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++: //
//
//  algoC.cpp - created by us162022
//
#include <iostream>
#include <queue>
using namespace std;
struct Node{
  int u,k,v[99];
  int distance;
};

int main(int argc, char *argv[])
{
  int n;
  Node node[100];
  queue<Node> que;

  cin >> n;

  for(int i=0; i<n; i++){
    cin >> node[i].u >> node[i].k;

    for(int j=0; j<node[i].k; j++)
      cin >> node[i].v[j];

    node[i].distance=-1;
  }

  node[0].distance = 0;
  que.push(node[0]);

  while(!que.empty()){
    Node fro = que.front();

    for(int i=0; i<fro.k; i++){
      int x = fro.v[i]-1;
  
      if(node[x].distance==-1)
	    node[x].distance = fro.distance+1;

      que.push(node[x]);
    }

    que.pop();
  }

  for(int i=0; i<n; i++)
    cout << node[i].u << " " << node[i].distance << endl;

}

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

#define REP(i, n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()
const int INF = 1e9;

using namespace std;
int adj[105][105] = {0};
int res[105] = {0};
int n;

int main() {
    cin >> n;
    REP(i, n){
        int u, k;
        cin >> u >> k;
        REP(j, k) {
            int tmp;
            cin >> tmp;
            adj[u-1][tmp-1] = 1;
        }
        res[i] = INF;
    }
    res[0] = 0;
    REP(i, n) REP(j, n)
        if(adj[i][j] != 0)
            res[j] = min(res[j], res[i]+1);

    REP(i, n){
        if(res[i] != INF)
            cout << i+1 << " " << res[i] << endl;
        else
            cout << i+1 << " -1" << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <stack>
#include <vector>
#include <algorithm>
#include <cmath>
#include <climits>
#include <cstring>
#include <queue>
#include <string>

using namespace std;

const double PI = 3.14159265358979;

int G[101][101];
bool visited[101];
int timex[101][2];
int deep[101];
int now_time = 1;
int n;

void dfs(int node) {

	if (!visited[node]) {
		visited[node] = 1;
		timex[node][0] = now_time++;
		for (int i = 0; i < n; i++)	{
			if (G[node][i] && visited[i] == 0) {
				dfs(i);
			}
		}
		timex[node][1] = now_time++;
	}
}

void dfs_stack(int node) {

	stack<int> st;
	st.push(node);
	visited[node] = 1;
	timex[node][0] = now_time++;
	while (!st.empty()) {
		int ver = st.top();

		bool flag = false;
		for (int i = 0; i < n; i++)	{
			if (G[ver][i] && visited[i] == 0) {
				visited[i] = 1;
				timex[i][0] = now_time++;
				st.push(i);
				flag = true;
				break;
			}
		}
		if (!flag) {
			timex[ver][1] = now_time++;
			st.pop();
		}
	}
}

void bfs(int node, bool reach) {

	queue<int> Q;
	visited[node] = 1;
	if (!reach) deep[node] = -1;
	Q.push(node);

	while (!Q.empty()) {

		int top = Q.front();
		Q.pop();
		for (int i = 0; i < n; i++)	{
			if (G[top][i] && !visited[i]) {
				Q.push(i);
				visited[i] = 1;
				if (reach)
					deep[i] = deep[top] + 1;
				else
					deep[i] = -1;
			}
		}
	}
}


int main() {
	
	cin >> n;

	for (int i = 0; i < n; i++)	{
		int id, degree;
		cin >> id >> degree;
		for (int j = 0; j < degree; j++) {
			int idx; cin >> idx;
			G[id - 1][idx - 1] = 1;
		}
	}

	bool first = true;
	for (int i = 0; i < n; i++) {
		if (!visited[i]) {
			bfs(i, first);
			first = false;
		}
	}
	

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

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()
{
  //入力
  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);

}