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 <iostream>
#include <set>
#include <vector>
#include <queue>
#include <stack>
#include <utility>

using namespace std;

typedef long long signed int ll;

constexpr ll NIL = -20000000000;

int g[101][101],n,d[101] = {-1};

int main() {
    cin >> n;
    for(int i = 0;i < n;i++) {
        int u,k,v;
        cin >> u >> k;
        for(int j = 0;j < k;j++) {
            cin >> v;
            g[u][v]++;
        }
    }
    queue<int> q;
    q.push(1);
    d[1] = 0;
    while(!q.empty()) {
        int u = q.front();q.pop();
        for(int i = 1;i <= n;i++) {
            if(g[u][i] && d[i] == -1)
            {
                d[i] = d[u]+1;
                q.push(i);
            }
        }
    }
    for(int i = 1;i <=n;i++) {
        cout << i << " " << d[i] <<endl;
    }
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define fi first
#define se second
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vl>;
using pl=pair<ll,ll>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[4]={1,0,-1,0};
const ll dx[4]={0,-1,0,1};
vvl G;
queue<ll> que;
void BFS(ll v,vl &dist){
    dist[v]=0;
    que.push(v);
    while(que.size()){
        ll v=que.front();
        que.pop();
        for(auto nv:G[v]){
            if(dist[nv]>dist[v]+1){
                dist[nv]=dist[v]+1;
                que.push(nv);
            }
        }
    }
}
int main(){
    ll N;cin>>N;
    vl id(N);
    G=vvl(N,vl());
    rep(i,N){
        cin>>id[i];
        ll k;cin>>k;
        rep(j,k){
            ll a;cin>>a;
            G[i].push_back(a-1);
        }
    }
    vl dist(N,INF);
    BFS(0,dist);
    vector<pl> ans(N);
    rep(i,N){
        ans[i].fi=id[i],ans[i].se=dist[i];
        if(ans[i].se==INF)ans[i].se=-1;
    }
    sort(all(ans));
    rep(i,N)cout<<ans[i].fi<<" "<<ans[i].se<<endl;
    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <map>
#include <numeric>
#include <string>
#include <cmath>
#include <iomanip>
#include <string>
#include <queue>
#include <list>
#include <stack>

typedef long long ll;
using namespace std;
const int mod = 1000000007;

void bfs(int node);
vector< vector<int> > Adj(100, vector<int>(100));
vector<int> dist(100, -1);
int n;

int main() {

    // input
    cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k; cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v; cin >> v; v--;
            Adj[i].push_back(v);
        }
    }

    dist[0] = 0;
    bfs(0);

    for (int i = 0; i < n; i++) {
        cout << i + 1 << ' ' << dist[i] << '\n';
    }

}

void bfs(int node) {

    queue<int> q;
    q.push(node);

    while (!q.empty()) {
        int cur = q.front();
        q.pop();
        for (auto v : Adj[cur]) {
            // visited
            if (dist[v] != -1) {
                continue;
            }
            // not visited
            else {
                dist[v] = dist[cur] + 1;
                q.push(v);
            }
        }
    }

}

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

#define MAX 100
static const int WHITE = 0; // not visit
static const int GRAY = 1; // visited
static const int BLACK = 2; // searched

int n;
int M[MAX][MAX] = { 0 };
int distance[MAX] = { 0 }; // ?????????????§??????????????????¢
int v_states[MAX] = { WHITE };


void breadthFirstSearch() {
	queue<int> vertices;

	vertices.push(0); // ?§????
	while (!vertices.empty()) {
		int u = vertices.front();
		v_states[u] = GRAY;
		vertices.pop();
		bool is_connected = false;
		for (int v = 0; v < n; v++) {
			if (M[u][v] == 1 && v_states[v] == WHITE) {
				::distance[v] = ::distance[u] + 1;
				vertices.push(v);
				v_states[v] = GRAY;
			}
		}
	}
	return;
}

int main() {
	cin >> n;

	for (int i = 0; i < n; i++) {
		int k, u;
		cin >> u >> k;
		u--;
		for (int j = 0; j < k; j++) {
			int v;
			cin >> v;
			v--;
			M[u][v] = 1;
		}
	}
	breadthFirstSearch();
	for (int i = 0; i < n; i++) {
		if (i && v_states[i] == WHITE) {
			::distance[i] = -1;
		}
		cout << i + 1 << ' ' << ::distance[i] << endl;
	}

	return 0;

}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = 1001001001;
const int MOD = 1000000007;

template <typename T>
void print(const T &v);

vector<int> dist(105, INF);
vector<int> grid[105];
int main()
{
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++)
        {
            int v;
            cin >> v;
            grid[u].push_back(v);
        }
    }
    queue<int> qe;
    qe.push(1);
    dist[1] = 0;

    while (!qe.empty())
    {
        int now = qe.front();
        qe.pop();
        for (int next : grid[now])
        {
            if (dist[next] <= dist[now] + 1)
            {
                continue;
            }
            if (dist[next] != INF)
            {
                dist[next] = dist[now] + 1;
                continue;
            }
            else
            {
                dist[next] = dist[now] + 1;
            }
            qe.push(next);
        }
    }
    for (int i = 1; i <= n; i++)
    {
        if (dist[i] != INF)
        {
            cout << i << ' ' << dist[i] << endl;
        }
        else
        {
            cout << i << ' ' << -1 << endl;
        }
    }
    return 0;
}

// Use For Debug
template <typename T>
void print(T const &v)
{
    for (int i = 0; i < v.size(); i++)
    {
        if (i)
            cout << ' ';
        cout << v[i];
    }
    cout << endl;
}