Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)

	g := make([][]int, n+1)
	d := make([]int, n+1)
	for i := 0; i < n; i++ {
		var u,k int
		fmt.Scan(&u)
		fmt.Scan(&k)
		g[u] = make([]int, k)
		for j := 0; j < k; j++ {
			fmt.Scan(&g[u][j])
		}

		d[i+1] = -1
	}

	q := [][]int{}
	q = append(q, []int{1, 0})
	for len(q) > 0 {
		pop := q[0]
		if len(q) > 1 {
			q = q[1:]
		} else {
			q = [][]int{}
		}
		if d[pop[0]] >= 0 {
			continue
		}
		d[pop[0]] = pop[1]

		for j := 0; j < len(g[pop[0]]); j++ {
			q = append(q, []int{g[pop[0]][j], pop[1]+1})
		}
	}

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

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

#define FOR(i, a, b) for(long long int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(long long int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000 //2000000000
#define LLINF 1000000000000000000 //9000000000000000000
#define PI 3.14159265358979

using namespace std;
typedef long long int ll;
typedef pair< long long int, long long  int> P;

int n;
int u, k, v;
int hour = 0;
int pos;
int d[101];
int gra[101][101] = {};
int color[101] = {};
queue<int>que;



int main(void) {
	cin >> n;
	
	FOR(i, 1, n) {
		cin >> u >> k;
		FOR(t, 1, k) {
			cin >> v;
			gra[u][v] = 1;
		}
	}

	FOR(i, 1, n) {
		d[i] = -1;
	}

	que.push(1);
	d[1] = hour;
	color[1] = 1;
	
	while (que.empty() != 1) {
		pos = que.front();
		que.pop();
		FOR(i, 1, n) {
			if (gra[pos][i] == 1 && color[i] == 0) {
				que.push(i);
				d[i] = d[pos] + 1;
				color[i] = 1;
			}
		}
	}

	FOR(i, 1, n) {
		cout << i << " " << d[i] << endl;
	}
	return 0;
}

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

using namespace std;
static const int N = 100;
static const int INFTY = (1 << 21);

int M[N][N] = {0}, d[N], n;

void bfs() {
  int u, v;
  queue<int> q;
  d[0] = 0;
  q.push(0);
  while (!q.empty()) {
    u = q.front();
    q.pop();
    for (v = 0; v < n; v++) {
      if (M[u][v] == 0) continue;
      if (d[u] != INFTY) continue;
      q.push(v);
      d[v] = d[u] + 1;
    }
  }
  for (u = 0; u < n; u++) {
    cout << u + 1 << ' ' << ((d[u] == INFTY) ? (-1) : d[u]) << endl;
  }
}

int main() {
  int u, v, k, i, j;

  for (i = 0; i < n; i++) {
    d[i] = INFTY;
  }

  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> u >> k;
    u--;
    for (j = 0; j < k; j++) {
      cin >> v;
      v--;
      M[u][v] = 1;
    }
  }

  bfs();

  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using pii=pair<int,int>;
using ll=long long;
using pll=pair<ll,ll>;

#define fi first
#define se second
#define pb push_back
#define rep(i,n) for(int i=0; i<(int)(n); i++)
#define MOD 1000000007

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
vector<vector<int> > G(110, vector<int>());

int main() {
	int N;
	cin >> N;
	int u,k;
	rep(i,N) {
		cin >> u >> k;
		u--;
		G[u] = vector<int>(k);
		rep(j,k) cin >> G[u][j], G[u][j]--;
	}

	queue<int> q;
	vector<int> dist(N, 1e9);
	dist[0] = 0;
	q.push(0);
	while(!q.empty()) {
		int p = q.front();
		q.pop();
		for(auto k : G[p]) {
			if(dist[k] > dist[p] + 1) {
				dist[k] = dist[p] + 1;
				q.push(k);
			}
		}
	}
	rep(i,N) if(dist[i] == 1e9) dist[i] = -1;
	rep(i,N) cout << i+1 << " " << dist[i] << endl;


  return 0;
}

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

using namespace std;

void bfs(vector<vector<int>> matrix) {
	
	//初期化
	//始点からの距離は1次元vectorで管理
	//始点から各頂点への距離をinf(-1)に設定
	int n = matrix.size();
	vector<int> d(n, -1);
	
	//始点をキューに入れる。始点の距離を0に
	queue<int> Q;
	Q.push(0);
	d.at(0) = 0;

	//以下ループ処理で距離の算出
	//キューが空になるまでこのループを回す
	while(! Q.empty()) {
		//キューの先頭の頂点を取り出す
		int head = Q.front();
		Q.pop();
		//その頂点から行ける点について-1なら
		for (int i = 0; i < matrix.at(0).size(); i++) {
			if (matrix[head][i] == 1 && d.at(i) == -1) {
				Q.push(i);
				d.at(i) = d.at(head) + 1;
			}
		}
	}

	// 表示
	for (int j = 0; j < d.size(); j++) {
		cout << j + 1 << " " << d.at(j) << endl;
	}
}

int main(void) {

	//標準入力を受け取る
	int n; //頂点数
	cin >> n;
	vector<vector<int>> matrix(n, vector<int>(n,0)); //隣接行列
	int u, k, v; //頂点番号、出次数、隣接する頂点番号
	for(int i = 0; i < n; i++) {
		cin >> u >> k;
		while(k--) {
			cin >> v;
			matrix.at(u-1).at(v-1) = 1; //有向グラフならこれだけ
			// matrix.at(v-1).at(u-1) = 1; //無向グラフなら反対向きも
		}
	}

	bfs(matrix);
	//
	// 隣接行列の表示
	// for(int i = 0; i < matrix.size(); i++) {
	//	 for(int j = 0 ;j < matrix.at(0).size(); j++) {
	//	 	cout << matrix.at(i).at(j) << " ";
	//	 }
	//	cout << endl;
	// }
}

//隣接リストどうやるの？

C++: #include <iostream>
#include <stdio.h>
#include <queue>
#define N 101
#define INFTY (1<<21)


int n;
int M[N][N];
int d[N];

void bfs(int u) {
    std::queue<int> Q;
    Q.push(u);
    for (int i = 0; i < n; i++) d[i] = INFTY;
    d[u] = 0;
    while ( ! Q.empty() ) {
        int j = Q.front();
        Q.pop();
        for (int v = 0; v < n; v++) {
            if (M[j][v] == 0) continue;
            if (d[v] != INFTY) continue;
            d[v] = d[u] + 1;
            Q.push(v);
        }
    }
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i+1, d[i]);
    }
}

int main() {
    int u, k, v;
    scanf("%d", &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++) {
        scanf("%d %d", &u, &k);
        u--;
        if (k == 0) continue;
        for (int j = 0; j < k; j++) {
            scanf("%d", &v);
            v--;
            M[u][v] = 1;
        }
    }
    
    bfs(0);
    
    return 0;
}

C++: //?????????P282-286 ????????§????????????

#include <iostream>
#include <queue>

using namespace std;
static const int N = 100;
static const int UNREACHABLE = -1;

int n, M[N][N];	//M[N][N]?????£??\??????
int d[N];	//???i????????¢???d[i]???????´???????

void bfs(int);

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;
		for(int j=0; j<k; j++){
			cin >> v;
			M[u-1][v-1] = 1;
		}
	}

	//?§???????0??¨?????????????????¢?´¢???????§?
	bfs(0);

	return 0;
}

void bfs(int s){
	queue<int> q;	//?¬?????¨???????????????????????¨??????????????????????????????\???
	q.push(s);

	for(int i=0; i<n; i++){		//???????????????????????¢?´¢??¶??????UNREACHABLE??????????????????
		d[i] = UNREACHABLE;
	}
	
	d[s] = 0;	//?§????????????¢???0???????????????

	int u;	//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] != UNREACHABLE) continue;	//??¢?´¢???????????????????????????
			d[v] = d[u] + 1;
			q.push(v);	//v????????¢?´¢?????£????????§???????????¢?´¢???????????¨??????v????????\??????????????????
		}
	}
	//???????????¨?§??????????????????¢?????¨???
	for(int i=0; i<n; i++){
		cout << i+1 << " " << d[i] << endl;
	}
}

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

int main(void) {
	int n, u, k, i, j, x, t, v;
	bool path[110][110];
	int d[110];
	memset(path, 0, sizeof(path));
	memset(d, -1, sizeof(d));
	cin >> n;
	for (i = 0;i<n;i++) {
		cin >> u >> k;
		u--;
		for (j = 0;j<k;j++) {
			cin >> x;
			x--;
			path[u][x] = true;
		}
	}

	queue<pair<int, int> > q;
	q.push({ 0,0 });
	while (!q.empty()) {
		v = q.front().first;
		t = q.front().second;
		q.pop();
		if (d[v] == -1)d[v] = t;
		else continue;

		t++;
		for (i = 0;i<n;i++) {
			if (path[v][i] && d[i] == -1) {
				q.push({ i,t });
			}
		}
	}

	for (i = 0;i<n;i++) {
		cout << i + 1 << " " << d[i] << endl;
	}

	return 0;
}