Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	visitedAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		visitedAt: -1,
		adjs: adjs,
	}
}

func (v *vertex) isVisited() bool {
	return v.visitedAt >= 0
}

func bfs(id vertexId, vqueue []vertexId, vertices []vertex) {
	vertex := &vertices[id-1]
	for _, vid := range vertex.adjs {
		if !vertices[vid-1].isVisited() {
			(&vertices[vid-1]).visitedAt = vertex.visitedAt+1
			vqueue = append(vqueue, vid)
		}
	}
	if len(vqueue) > 0 {
		nextId := vqueue[0]
		nextVqueue := vqueue[1:]
		bfs(nextId, nextVqueue, vertices)
	}
}

func solveBfs(vertices []vertex) {
	vertex := &vertices[0]
	vertex.visitedAt = 0
	vqueue := make([]vertexId, 0)
	bfs(vertex.id, vqueue, vertices)
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	solveBfs(vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d\n", vertices[i].id, vertices[i].visitedAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func nextInt(sc *bufio.Scanner) (int, error) {
	return strconv.Atoi(nextText(sc))
}

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

int n;
vector<int> G[110];
int d[110];

void bfs(){
  queue<int> que;
  for(int i=0; i<n; i++){
    d[i] = -1;
  }
  d[0] = 0;
  que.push(0);
  while(!que.empty()){
    int v = que.front(); que.pop();
    for(int i=0; i<G[v].size(); i++){
      int nv = G[v][i];
      if(d[nv] < 0){
        que.push(nv);
        d[nv] = d[v] + 1;
      }
    }
  }
}

int main(){
  cin >> n;
  for(int i=0; i<n; i++){
    int u, k; cin >> u >> k;
    for(int i=0; i<k; i++){
      int c; cin >> c;
      G[u-1].push_back(c-1);
    }
  }
  bfs();
  for(int i=0; i<n; i++){
    cout << i+1 << " " << d[i] << endl;
  }
}

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

int n;
char c[101];
int g[101][101];
int t = 0;
int visit[101];
int finish[101];
int d[101];
int dist = 0;

void bfs(int start) {
    t++;
    queue<int> q;
    q.push(start);
    c[start] = 'g';
    visit[start] = t;
    while(!q.empty()) {
        t ++;
        int now = q.front();
        dist ++;
        for (int i = 1; i <= n ; ++i) {
            if(g[now][i] && c[i] == 'w') {
                q.push(i);
                c[i] = 'g';
                visit[i] = t;
                d[i] = d[now] + 1;
            }
        }
        q.pop();
        c[now] = 'b';
        finish[now] = t;
    }
}
int main() {
    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;
            g[u][v] = 1;
        }
    }

    for (int l = 0; l < n; ++l) {
        c[l+1] = 'w';
    }

    for (int i1 = 1; i1 <=n ; ++i1) {
        d[i1] = -1;
    }
    for (int m = 1; m <= n ; ++m) {
        d[1] = 0;
        if(c[m] == 'w') bfs(m);
        break;

    }
    for (int j1 = 1; j1 <=n ; ++j1) {
        cout << j1 << " " << d[j1] << 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() {
  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++: #include <iostream>
#include<queue>
using namespace std;
#define INF 9999999

int G[101][101];
int dis[101];
int main(){
  int n;
  cin>>n;
  for(int i=0;i<n;i++){
    int u,k;
    cin>>u>>k;
    for(int j=1;j<=k;j++){
      G[u][0]=k;
      cin>>G[u][j];
    }
  }
  fill(dis,dis+101,INF);
  dis[1]=0;
  queue<int> Q;
  Q.push(1);
  while(!Q.empty()){
    int num=Q.front(); Q.pop();
    for(int i=1;i<=G[num][0];i++){
      int k=G[num][i];
      dis[k]=min(dis[num]+1,dis[k]);
      Q.push(k);
    }
  }
  for(int i=1;i<=n;i++){
    cout<<i<<" "<<dis[i]<<"\n";
  }
}

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 (!p.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() {

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

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

  bfs(0);

  return 0;
}

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

using namespace std;

int main() {
	int n, u, k, v;
	cin >> n;
	vector<int> ans(n,100000000000);
	vector<vector<int>> adj(n);
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		while (k--)cin >> v, adj[u-1].push_back(v-1);
	}
	queue<pair<int, int>> q;//<idx,path>
	q.push(pair<int, int>(0, 1));
	while (!q.empty()) {
		auto tmp = q.front(); q.pop();
		ans[tmp.first] = min(ans[tmp.first], tmp.second);
		for (int i = 0; i < adj[tmp.first].size(); i++) q.push(pair<int, int>(adj[tmp.first][i], tmp.second+1));
	}
	for (int i = 0; i < n; i++)	cout << i + 1 << " " << ans[i]-1 << endl;
	
}