Go: package main

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

var distance []int

type queue struct {
	q    []int
	head int
	tail int
}

func (q *queue) push(n int) {
	q.q[q.tail] = n
	q.tail++
}

func (q *queue) pop() int {
	q.head++
	return q.q[q.head-1]
}

func (q *queue) isEmpty() bool {
	return q.head == q.tail
}

func makeAdjList() [][]int {
	var n int
	fmt.Scanf("%d", &n)

	adj := make([][]int, n)
	for i := 0; i < n; i++ {
		adj[i] = make([]int, n)
	}

	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		sc.Scan()
		nodeInfo := strings.Split(sc.Text(), " ")
		outDegree, _ := strconv.Atoi(nodeInfo[1])

		if outDegree > 0 {
			for k := 0; k < outDegree; k++ {
				j, _ := strconv.Atoi(nodeInfo[k+2])
				j-- // convert 1 based to 0 based
				adj[i][j] = 1
			}
		}
	}

	return adj
}

func bfs(graph [][]int, s int) {
	distance = make([]int, len(graph))

	infty := -1
	for i := 0; i < len(distance); i++ {
		distance[i] = infty
	}
	distance[s] = 0

	q := &queue{make([]int, 1000), 0, 0}
	q.push(s)

	for !q.isEmpty() {
		u := q.pop()
		for i := 0; i < len(graph); i++ {
			if graph[u][i] == 0 {
				continue // u, i間に辺がない場合
			}
			if distance[i] != infty {
				continue // 訪問済みの場合
			}
			// 訪問するnodeの始点からの距離を設定し、訪問キューに入れる
			distance[i] = distance[u] + 1
			q.push(i)
		}
	}

	// print distance
	for i, d := range distance {
		fmt.Printf("%d %d\n", i+1, d)
	}
}

func main() {
	adj := makeAdjList()
	bfs(adj, 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);

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;
}

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;
    }
}

C++: #include<stdio.h>


#define MAX 101
#define WHITE 2
#define GRAY 1
#define BLACK 0

int col[MAX], d[MAX], a[MAX][MAX]; 
 
int n, h= 0, t = 0;


int Que[MAX];


/*Qの操作*/
 int Dequeque(){
  h++;
  return Que[h - 1];
}
void Enqueque(int b){
  Que[t] = b;
  t++;
}

 
void BFS(int s){
  int i, u;
  for(i = 1; i < n+1; i++){
      col[i] = WHITE;


      d[i] = -1;
  }
  d[s] = 0;
  

  col[s] = GRAY;
  
  Enqueque(s);
 
  while(h != t){
    u = Dequeque();
    for(i = 1; i <= n; i++){
      if((col[i] == WHITE) && (a[u][i] == 1)){


    col[i] = GRAY;
    d[i] = d[u] + 1;
    Enqueque(i);
      }
    }
   

    col[u] = BLACK;
  }
}
 

  
int main(){
 
  scanf("%d", &n);
 
  int i, u, j,y=1,e;



  /*配列の初期化*/
  for(i = 1; i < n+1; i++){
    for(j = 1; j < n+1; j++){
     

 a[i][j] = 0;

    }
  }

  int x; 
  for(i = 1; i < n+1; i++){

    scanf("%d%d",&u,&e);
    for(j = 1; j <= e; j++){
      scanf("%d", &x);
      a[i][x] = 1;
    }
  }
 
  BFS(y);
   
  for(i = 1; i < n+1; i++){
    printf("%d ", i);
    printf("%d\n", d[i]);
  }
  return 0;
}

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

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    vector<int> G[n];
    for(int i = 0; i < n; i++){
        int p, k;
        cin >> p >> k;
        for(int j = 0; j < k; j++){
            int a;
            cin >> a;
            G[p - 1].push_back(a - 1);
        }
    }

    vector<int> D(n, 1e9);
    D[0] = 0;
    queue<int> q;
    q.push(0);

    while(!q.empty()){
        int now = q.front();
        q.pop();

        for(int i = 0; i < G[now].size(); i++){
            int to = G[now][i];
            if(D[now] + 1 < D[to]){
                D[to] = D[now] + 1;
                q.push(to);
            }
        }
    }

    for(int i = 0; i < n; i++){
        cout << i + 1 << ' ' << (D[i] == 1e9 ? -1 : D[i]) << endl;
    }

    return 0;
}

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

using namespace std;
typedef long long ll;

#define INF (long long)(1e9+7)
#define REP(i,n) for(ll i = 0; i < n; i++)
#define REP1(i,n) for(ll i = 1; i <= n; i++)

using Graph = vector<vector<int>>;


int main(void)
{
  int n;
  cin >> n;
  Graph G(n);
  int u, k;
  REP(j, n) {
    cin >> u >> k;
    u--;
    REP(i, k) {
      int v;
      cin >> v;
      v--;
      G[u].push_back(v);
      //      G[v].push_back(u);
    }
  }

  vector<int> dist(n, -1);
  queue<int> que;

  dist[0] = 0;
  que.push(0);

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

    for(int nv : G[v]) {
      if(dist[nv] != -1) continue;

      dist[nv] = dist[v] + 1;
      que.push(nv);
    }
  }
  REP(i, n) cout << i + 1 << " " << dist[i] << endl;

}

C++: #include <iostream>
#include <algorithm>
#include <string>
#include <stack>
#include <cstdlib>
#include <queue>
#include <vector>
#include <set>

using namespace std;
int n,m,l,p;
bool a[100][100];
int D[100];
void bfs( int src) {
	queue<int> Q;
	Q.push(src);
	D[src]=0;
	while( ! Q.empty() ) {
		int cur = Q.front();
		Q.pop();
		for(int dst = 0; dst < n; dst++ ) {
			if( D[dst] == 0 && a[cur][dst] == 1 ) {
				D[dst] = D[cur] + 1;
				Q.push(dst);
			}
		}
	}
	for (int i = 0; i < n;i++) {
	cerr << i+1 <<  " " << D[i] <<  endl;
	}
}

int main() {
	cin >> n;
	for ( int i = 0;i < n;i++) {
		D[i] = 0;
		for(int j= 0; j < n;j++) {
			a[i][j] = 0;
		}
	}
	for (int i = 0;i < n; i++){
		cin >> m;
		cin >> l;
		for(int j = 0; j < l;j++) {
			cin >> p;
			a[m-1][p-1] = 1;
		}
	}
	bfs(0);
}