Go: package main

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

type AdjacentList struct {
	matrix [][]int
}

func NewEmptyAdjacentList(dim int) *AdjacentList {
	matrix := make([][]int, dim)
	for i := 0; i < dim; i++ {
		matrix[i] = make([]int, dim)
	}
	return &AdjacentList{matrix: matrix}
}

func (al *AdjacentList) set(node int, adjacent int) {
	al.matrix[node-1][adjacent-1] = 1
}

func (al *AdjacentList) findAdjacentsFor(node int) []int {
	adjacents := []int{}
	for i, v := range al.matrix[node-1] {
		if v == 1 {
			adjacents = append(adjacents, i+1)
		}
	}
	return adjacents
}

type DistanceList struct {
	list []int
}

func NewDistanceList(dim int) *DistanceList {
	list := make([]int, dim)
	for i := 0; i < dim; i++ {
		list[i] = -1
	}
	return &DistanceList{list: list}
}

func (dl *DistanceList) set(node int, distance int) {
	dl.list[node-1] = distance
}

func (dl *DistanceList) get(node int) int {
	return dl.list[node-1]
}

func (dl *DistanceList) isVisited(node int) bool {
	return dl.list[node-1] >= 0
}

type Position struct {
	node     int
	distance int
}

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

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

	al := NewEmptyAdjacentList(dim)

	for i := 1; i <= dim; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}

		adjacentNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		for j := 0; j < adjacentNum; j++ {
			adjacent, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			al.set(node, adjacent)
		}
	}

	dl := NewDistanceList(dim)

	bfs(al, dl)

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

func bfs(al *AdjacentList, dl *DistanceList) {
	stack := []Position{Position{node: 1, distance: 0}}
	for len(stack) > 0 {
		currentPosition := stack[0]
		stack = stack[1:]
		if !dl.isVisited(currentPosition.node) {
			dl.set(currentPosition.node, currentPosition.distance)
		}
		for _, v := range al.findAdjacentsFor(currentPosition.node) {
			stack = append(stack, Position{node: v, distance: currentPosition.distance + 1})
		}
	}
}

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

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

#define FOR(i,k,n) for (int (i)=(k); (i)<(n); ++(i))
#define REP(i,n) FOR(i,0,n)
using namespace std;

int main(){
    int n,u,k,v,src=0;
    cin >> n;
    int D[n],g[n][n];
    REP(i,n){
        D[i] = -1;
        REP(j,n){
            g[i][j] = 0;
        }    
    }
    REP(i,n){ 
        cin >> u >> k;
            REP(j,k){
                cin >> v;
                g[v-1][u-1] = 1;
            }
    }

    queue<int> Q;
    Q.push(src);
    D[src] = 0;
    while (!Q.empty()) {
        int cur = Q.front();
        Q.pop();
            REP(i,n){
                if(g[i][cur] == 1 && D[i] < 0){
                    D[i] = D[cur] + 1;
                    Q.push(i);
                }
            }
    }

    REP(i,n){
        cout << i+1 << " " << D[i] << endl;    
    }
}

C++: #include <stdio.h>
#include <limits.h>
#include <queue>

#define N 100

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

static void bfs(int s)
{
    std::queue<int> q;
    q.push(s);

    d[s] = 0;

    while (!q.empty()) {
        int u = q.front();
        q.pop();
        for (int v = 0; v < n; v++) {
            if (M[u][v] == 0)
                continue;
            if (d[v] != INT_MAX)
                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_MAX) ? -1 : d[i]);
    }
}

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

C++: #include <bits/stdc++.h>
using namespace std;
const int INF=1145141919;

#define debug cout<<"debug"<<endl;

int main(){

  int n;
  cin>>n;

  vector <int> g[n];

  for(int i=0;i<n;i++){

    int u,k;
    cin>>u>>k; u--;

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

  }

  int dis[n];
  fill(dis,dis+n,INF);
  dis[0]=0;

  queue <int> bfs;
  bfs.push(0);

  for(;!bfs.empty();){

    int check=bfs.front(); bfs.pop();

    for(int i=0;i<(int)g[check].size();i++){

      int next=g[check][i];

      if(dis[next]>dis[check]+1){
	dis[next]=dis[check]+1;
	bfs.push(next);
      }

    }
  }

  for(int i=0;i<n;i++)
    cout<<i+1<<" "<<(dis[i]==INF?-1:dis[i])<<endl;

  return 0;

}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <string>
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>

using namespace std;

// ---------------------
// repetition
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

// debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

// ---------------------
#define INF 922337203685477580
typedef long long ll;

int matrix[110][110];
int dist[110];
int visited[110];
int n;
queue<int> Q;

int main() {
  REP(x, 110) {
    REP(y, 110) {
      matrix[x][y] = 0;
    }
    dist[x] = (1 << 15);
    visited[x] = 0;
  }

  // int n;
  cin >> n;

  REP(_, n) {
    int v, num;
    cin >> v >> num;

    REP(i, num) {
      int cv;
      cin >> cv;
      matrix[v][cv] = 1;
    }
  }

  dist[1] = 0;
  Q.push(1);

  while (!Q.empty()) {
    int f = Q.front(); Q.pop();
    visited[f] = 1;

    // int updated = 0;
    FOR(v, 1, n + 1) {
      if (matrix[f][v]) {
        if (dist[v] > dist[f] + 1) {
          dist[v] = dist[f] + 1;
          // updated = 1;
          // cout << "update for " << v  << endl;
        }
        if (!visited[v]) {
          Q.push(v);
        }
      }
    }
    // if (updated == 0 && Q.empty()) {
    //   cout << "break!" << endl;
    //   break;
    // }
  }


  FOR(v, 1, n + 1) {
    if (dist[v] == (1 << 15)) {
      cout << v << " -1" << endl;
    } else {
      cout << v << " " << dist[v] << endl;
    }
  }


  return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <iostream>
#include <string>
#include <map>
#include <queue>
#include <stdio.h>
#include <math.h>


using namespace std;

typedef long long ll;

typedef vector<vector<int>> vvi;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<ll> vll;

typedef pair<int, int> P;

typedef queue<int> qi;
typedef queue<string> qs;


#define rep(i, n) for(int i=0; i<(n); ++i)
#define repp(i, a, b) for(int i = (a); i <= (b); i++)
#define Rep(i, n) for(int i=n; i >= 0; i--)

#define all(v) v.begin(), v.end()
//sort( all(v) )　などと使える

int main() {
	int n; cin >> n;
	vector<vector<int>> G(n);
	rep(i, n) {
		int u, k; cin >> u >> k;
		u--;
		//G[u].resize(k);

		rep(j, k) {
			int v; cin >> v;
			v--;
			G[u].push_back(v);
		}
	}

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

	dist[0] = 0;
	queue<int> que;
	que.push(0);

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

		for (auto nv : G[v]) {
			if (dist[nv] != -1) continue;
			else {
				dist[nv] = dist[v] + 1;
				que.push(nv);
			}
		}
	}

	rep(i, n) {
		cout << i + 1 << " " << dist[i] << endl;
	}

	//return 0;
}