Go: package main

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

type Pair struct {
	v int
	d int
}

type Queue []Pair

func (q *Queue) push(v Pair) {
	*q = append(*q, v)
}

func (q *Queue) pop() Pair {
	v := (*q)[0]
	*q = (*q)[1:]
	return v
}

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

	nVerts := scanInt(sc)
	graph := make([][]int, nVerts+1)

	for i := 0; i < nVerts; i++ {
		u := scanInt(sc)
		nDegrees := scanInt(sc)

		graph[u] = make([]int, nDegrees)
		for d := 0; d < nDegrees; d++ {
			graph[u][d] = scanInt(sc)
		}
	}

	paths := make([]int, nVerts+1)

	queue := Queue(make([]Pair, 0))
	queue.push(Pair{1, 1})
	paths[1] = 1

	for len(queue) > 0 {
		p := queue.pop()
		d := p.d + 1
		for _, v := range graph[p.v] {
			if paths[v] == 0 {
				paths[v] = d
				queue.push(Pair{v, d})
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 1; i <= nVerts; i++ {
		fmt.Fprintf(w, "%d %d\n", i, paths[i]-1)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

C++: #include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <ctime>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

#define rep(i,n)   for (int i = 0; i < (n); ++i)
#define sort(a)    sort((a).begin(), (a).end());
#define uniq(a)    SORT(a);(a).erase(unique((a).begin(), (a).end()), (a).end());
#define find(a,x)  find((a).begin(), (a).end(), (x)) != (a).end()
#define reverse(a) reverse((a).begin(), (a).end());
#define out(d) cout << (d);
#define outl(d) std::cout<<(d)<<"\n";
#define Yes() printf("Yes\n");
#define No() printf("No\n");
#define YES() printf("YES\n");
#define NO() printf("NO\n");
#define ceil(x, y) ((x + y - 1) / (y))

using namespace std;
using ll = long long;
using P = pair<ll,ll>;

const ll MOD = 1000000007; // 10^9 + 7

const int MAX_N = 100;
int d[MAX_N + 1];
int N;
vector<vector<int>> g(MAX_N + 1);

void bfs() {
  queue<P> q;
  q.push(make_pair(1, 0));

  while (!q.empty()) {
    P p = q.front(); q.pop();
    int node = p.first;
    int dist = p.second;

    if (d[node] >= 0) continue;

    d[node] = dist;
    for (int i = 0; i < g[node].size(); i++) {
      q.push(make_pair(g[node][i], dist + 1));
    }
  }
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  srand((unsigned)time(NULL));

  cin >> N;
  for (int i = 0; i < N; i++) {
    int u; cin >> u;
    int k; cin >> k;
    for (int ki = 0; ki < k; ki++) {
      int tmp; cin >> tmp;
      g[u].push_back(tmp);
    }
    sort(g[u])
  }
  memset(d, -1, sizeof(d));

  bfs();

  for (int i = 1; i <= N; i++) {
    cout << i << " " << d[i] << endl;
  }
}

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 <bits/stdc++.h>

using namespace std;

int main() {
  int n; cin >> n;

  vector<vector<int>> G(n, vector<int>());

  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);
    }
  }

  vector<int> dist(n, 1000);
  dist[0] = 0;

  for (int i = 0; i < 100; i++) {
    for (int j = 0; j < n; j++) {
      for (auto k: G[j]) {
        dist[k] = min(dist[k], dist[j] + 1);
      }
    }
  }

  for (int i = 0; i < n; i++) {
    cout << i + 1 << ' ';
    if (dist[i] == 1000) {
      cout << -1 << endl;
    } else {
      cout << dist[i] << endl;
    }
  }
}

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<stdio.h>
#include<stack>
#include<iostream>
#include<string>
using namespace std;

int n = 0;
int u = 0;
int k[101];
int v[101][101];
int Short[101] = { 0 };
//into n = 0;
int p = 0;
int fptr = 0;
int lptr = 0;
int x1[10000];
int y1[10000];
void Enqueue(int y, int x)
{
	x1[lptr] = x;
	y1[lptr] = y;
	lptr = (lptr + 1) % n;
}
void bfs(int l) {
	int i;
	while (fptr!=lptr) {
		l=x1[fptr];
		p=y1[fptr];
		fptr = (fptr + 1) % n;
		if(Short[l]!=-1){
			continue;
		}
		for(i=0;i<k[l];i++){
			if(v[l][i]){
				Enqueue(p+1,v[l][i]);
			}
		}
		//Enqueue(v[l][in]);
		Short[l]=++p;
	}
}
int main()
{
	int i;
	int j;
	cin >> n;
	for (i = 0; i < n; i++) {
		cin >> u;
		cin >> k[u];
		for (j = 0; j < k[u]; j++) {
			cin >> v[u][j];
		}
	}
	Enqueue(-1,1);
	for(i=0;i<n+1;i++){
		Short[i]=-1;
	}
	bfs(0);
	cout << "\n";
	
	for (i = 1; i < n + 1; i++) {
		cout << i << " " << Short[i] << endl;
	}
}

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

class TNode
{
	std::list<TNode*> FNexts;
	int  FDistance;
public:
	TNode()
	: FDistance(-1)
	{
	}
	
	int GetDistance()const {return FDistance;}
	
	void Push(TNode* New)
	{
		FNexts.push_back(New);
	}
	
	void Visit(int Distance)
	{
		if(FDistance >= 0 && Distance > FDistance) return;
		FDistance = Distance;
		for(std::list<TNode*>::iterator It = FNexts.begin(); It != FNexts.end(); ++It){
			(*It)->Visit(Distance + 1);
		}
	}
};

class TGraph
{
	std::vector<TNode*> FNodes;
public:
	TGraph(int Count)
	: FNodes(Count + 1)
	{
		for(int i = 1; i < Count + 1; ++i){
			FNodes[i] = new TNode();
		}
	}
	
	~TGraph()
	{
		for(unsigned int i = 1; i < FNodes.size(); ++i){
			delete FNodes[i];
		}
	}
	
	void InputNode()
	{
		int Index;
		std::cin >> Index;
		int BranchCount;
		std::cin >> BranchCount;
		for(int i = 0; i < BranchCount; ++i){
			int Target;
			std::cin >> Target;
			FNodes[Index]->Push(FNodes[Target]);
		}
	}
	
	void BreathFirstSearch()
	{
		FNodes[1]->Visit(0);
	}
	
	int Distance(int Target)const
	{
		return FNodes[Target]->GetDistance();
	}
};

int main()
{
	int Count;
	std::cin >> Count;
	TGraph Graph(Count);
	for(int i = 0; i < Count; ++i){
		Graph.InputNode();
	}
	Graph.BreathFirstSearch();
	
	for(int i = 0; i < Count; ++i){
		std::cout << i + 1 << " " << Graph.Distance(i + 1) << std::endl;
	}
	return 0;
}