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 <iostream>
#include <queue>
using namespace std;
static const int N = 100;
static const int NAV = -1;

int M[N][N];

void bfs(int s, int n, int M[N][N], int d[]) {
    queue<int> Q;
    for (int i = 0; i < n; i++) d[i] = NAV;
    d[s] = 0;
    Q.push(s);

    int u;
    while (!Q.empty()) {
        u = Q.front();
        Q.pop();
        for (int v = 0; v < n; v++) {
            if (M[u][v] != 0 && d[v] == NAV) {
                d[v] = d[u] + 1;
                Q.push(v);
            }
        }
    }
}

int main() {
    int n, 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;
        }
    }

    int d[n];
    bfs(0, n, M, d);

    for (int i = 0; i < n; i++) {
        cout << i + 1 << " " << 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 n, M[N][N];
int d[N]; // ?????¢??§?¨??????¶???(color)???????????????

void bfs(int s) {
  queue<int> q; // ?¨?????????????????????? queue ????????¨
  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, i, j;

  cin >> n;
  for (i = 0; i < n; i++) {
    for (j = 0; j < n; j++) M[i][j] = 0;
  }

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

  bfs(0);

  return 0;
}

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

queue<int>Q;
int n, M[101][101], s[101];

void bfs()
{
	Q.push(1);
	s[1] = 0;

	int id = 1;

	while (true)
	{
		for (int pid = 1; pid <= n; pid++)
		{
			if (M[id][pid] == 1 && s[pid] == -1)
			{
				Q.push(pid);
				s[pid] = s[id] + 1;
			}
		}

		Q.pop();

		if (!Q.empty())
			id = Q.front();
		else
			break;
	}
}

int main()
{
	int id, pid, k;
	memset(M, 0, sizeof(M));
	memset(s, -1, sizeof(s));

	cin >> n;

	for (int i = 1; i <= n; i++)
	{
		cin >> id >> k;

		for (int j = 1; j <= k; j++)
		{
			cin >> pid;
			M[id][pid] = 1;
		}
	}

	bfs();

	for (int i = 1; i <= n; i++)
		cout << i << " " << s[i] << endl;

	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int, int>;

int main()
{
    int n;
    cin >> n;
    vector<vector<bool>> G(n, vector<bool>(n));
    rep(i, n)
    {
        int u, k;
        cin >> u >> k;
        rep(j, k)
        {
            int v;
            cin >> v;
            G[u - 1][v - 1] = true;
        }
    }
    queue<int> Q;
    Q.push(0);
    vector<bool> visited(n);
    vector<int> dis(n, -1);
    visited[0] = true;
    dis[0] = 0;
    while (!Q.empty())
    {
        int v = Q.front();
        Q.pop();
        rep(i, n)
        {
            if (G[v][i] && !visited[i])
            {
                Q.push(i);
                dis[i] = dis[v] + 1;
                visited[i] = true;
            }
        }
    }
    rep(i, n) printf("%d %d\n", i + 1, dis[i]);
    return 0;
}

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

const int nIMPOS = -1;
struct StDist
{
  int m_nDist;
  int m_nFromMeTo;

  StDist(int nDist) : m_nDist(nDist), m_nFromMeTo(0)
  { }
};

void fnInput(vector<vector<int>>& rvvnAdjcy, vector<StDist>& rvoDist)
{
  int nxSiz;
  cin >> nxSiz;

  rvvnAdjcy.resize(nxSiz + 1, vector<int>(nxSiz + 1, 0));
  for (int i = 0; i < nxSiz; ++i)
  {
    int nx, nySiz;
    cin >> nx >> nySiz;
    for (int j = 0; j < nySiz; ++j)
    {
      int ny;
      cin >> ny;
      rvvnAdjcy[nx][ny] = 1;
    }
  }
  StDist oDist(nIMPOS);
  rvoDist.resize(nxSiz + 1, oDist);
}

void fnBreadthFirstSearch(const vector<vector<int>>& cnrvvnAdjcy, 
                          queue<int>& rqnBFSrch, vector<StDist>& rvoDist)
{
  while (rqnBFSrch.size())
  {
    int nx = rqnBFSrch.front(); rqnBFSrch.pop();
    if (rvoDist[nx].m_nDist == nIMPOS)  continue;

    for (int ny = 1; ny < cnrvvnAdjcy[nx].size(); ++ny)
    {
      if (cnrvvnAdjcy[nx][ny] == 1  &&
          rvoDist[nx].m_nFromMeTo == 0)
      {
        int nDist = rvoDist[nx].m_nDist + 1;
        if (rvoDist[ny].m_nDist == nIMPOS)
          rvoDist[ny].m_nDist = nDist;
        else
          rvoDist[ny].m_nDist = min(rvoDist[ny].m_nDist, nDist);

        rqnBFSrch.push(ny);
      }
    }
    rvoDist[nx].m_nFromMeTo = 1;
  }
}

void fnResult(const vector<StDist>& cnrvoDist)
{
  for (int i = 1; i < cnrvoDist.size(); ++i)
    cout << i <<  " " << cnrvoDist[i].m_nDist << endl;
}

int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  vector<vector<int>> vvnAdjcy;
  queue<int>  qnBFSrch;
  vector<StDist> voDist;

  fnInput(vvnAdjcy, voDist);

  voDist[1].m_nDist = 0;
  qnBFSrch.push(1);
  fnBreadthFirstSearch(vvnAdjcy, qnBFSrch, voDist);
  fnResult(voDist);

  return 0;
}

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

using namespace std;


int main() {
    int n, u, k; cin >> n;
    vector<vector<int> > v(n);
    for (int i = 0; i < n; ++i) {
        cin >> u >> k;
        vector<int> v0(k);
        for (int j = 0; j < k; ++j) {
            cin >> v0[j];
            --v0[j];
        }
        v[u-1] = v0;
    }
    queue<pair<int, int> > q;
    vector<bool> visited(n, false);
    q.push(make_pair(0, 0));
    visited[0] = true;
    vector<int> ans(n, -1);
    ans[0] = 0;
    while(!q.empty()) {
        pair<int, int> x = q.front(); q.pop();
        int cnt = x.second + 1;
        for (int i = 0; i < v[x.first].size(); ++i) {
            int j = v[x.first][i];
            if (!visited[j]) {
                q.push(make_pair(j, cnt));
                visited[j] = true;
                ans[j] = cnt;
            }
        }
    }
    for (int i = 0; i < n; ++i) cout << i + 1 << " " << ans[i] << endl;
    return 0;
}

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

using namespace std;

const static int N=100;
const static 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[u]!=0){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,v,k;
    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; k++){
            cin>>v;
            v--;
            M[u][v]=1;
        }
    }
    bfs(0);
    return 0;
}