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) {
			if !dl.isVisited(v) {
				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 <bits/stdc++.h>
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;
const int N = 100;
const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;
const int INFTY = (1<<21);

int n;
int M[N][N] = {0};
int colur[N] = {WHITE};
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,v,i,j,k;
    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(0);

    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define int long long

const int N = 1000;
vector< vector<int> > G(N);
int d[N],visited[N];

void bfs(){

  fill(d+2,d+N,N);
  queue<pair<int,int>> q;
  q.push({1,1});
  while(!q.empty()){
    auto p = q.front(); q.pop();
    int s = p.first;
    int cnt = p.second;
    for(int i = 0; i < G[s].size(); i++){
      int v = G[s][i];
      d[v] = min(d[v],cnt);
      if(!visited[v]) q.push({v,cnt+1});
      visited[v] = 1;
    }
  }
}

signed main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  int n; 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;
      G[u].push_back(v);
    }
  }

  bfs();
  for(int i = 1; i <= n; i++){
    if(d[i] != N) cout << i << " " << d[i] << endl;
    else cout << i << " " << -1 << endl;
  }

  return 0;
}

C++: #include <stdio.h>
#define MAX 101

int A[MAX][MAX], s[MAX], h[MAX];

void serch(int x, int y){
  int i;
  h[x] = y;
  for(i=1; i<=s[x]; i++){
    if(h[A[x][i]] > y)
      serch(A[x][i], y+1);
  }
}

int main(){
  int i, j, k, n;
  
  scanf("%d", &n);
  for(i=1; i<=n; i++){
    h[i] = 10000;
    for(j=1; j<=n; j++)
      A[i][j] = 0;
  }
  
  for(i=1; i<=n; i++){
    scanf("%d", &k);
    scanf("%d", &s[k]);
    for(j=1; j<=s[k]; j++)
      scanf("%d", &A[k][j]);
  }
  
  serch(1,0);
  
  for(i=1; i<=n; i++){
    if(h[i] == 10000)
      h[i] = -1;
    printf("%d %d\n", i, h[i]);
  }
  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(void) {
  int u, k, v;
  cin >> n;
  //init
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < n; j++) {
      M[i][j] = 0;
    }
  }


  //??£??\???????????¨??????0-origin?????£??\???????????????
  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<cstdio>
#include<iostream>
#include<queue>
using namespace std;
#define MAX 100
#define INFTY 1 << 21

int n, M[MAX][MAX];
int dist[MAX];

void bfs_visit(int u){
    queue<int> q;
    q.push(u);
    int v;
    for(v = 0; v < n; v++) dist[v] = INFTY;
    dist[u] = 0;

    while(!q.empty()){
        u = q.front();
        q.pop();
        for(v = 0;  v < n; v++){
            if(M[u][v] == 0) continue;
            if(dist[v] != INFTY) continue;
            dist[v] = dist[u] + 1;
            q.push(v);
        }

    }
    for(int i = 0; i < n; i++){
            cout << i + 1 << " " << (dist[i] == INFTY ? -1 : dist[i]) << endl;
    }
}

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

    bfs_visit(0);

    return 0;
}