Go: package main

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

var distance []int

type queue struct {
	q    []int
	head int
	tail int
}

func (q *queue) push(n int) {
	q.q[q.tail] = n
	q.tail++
}

func (q *queue) pop() int {
	q.head++
	return q.q[q.head-1]
}

func (q *queue) isEmpty() bool {
	return q.head == q.tail
}

func makeAdjList() [][]int {
	var n int
	fmt.Scanf("%d", &n)

	adj := make([][]int, n)
	for i := 0; i < n; i++ {
		adj[i] = make([]int, n)
	}

	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		sc.Scan()
		nodeInfo := strings.Split(sc.Text(), " ")
		outDegree, _ := strconv.Atoi(nodeInfo[1])

		if outDegree > 0 {
			for k := 0; k < outDegree; k++ {
				j, _ := strconv.Atoi(nodeInfo[k+2])
				j-- // convert 1 based to 0 based
				adj[i][j] = 1
			}
		}
	}

	return adj
}

func bfs(graph [][]int, s int) {
	distance = make([]int, len(graph))

	infty := -1
	for i := 0; i < len(distance); i++ {
		distance[i] = infty
	}
	distance[s] = 0

	q := &queue{make([]int, 1000), 0, 0}
	q.push(s)

	for !q.isEmpty() {
		u := q.pop()
		for i := 0; i < len(graph); i++ {
			if graph[u][i] == 0 {
				continue // u, i間に辺がない場合
			}
			if distance[i] != infty {
				continue // 訪問済みの場合
			}
			// 訪問するnodeの始点からの距離を設定し、訪問キューに入れる
			distance[i] = distance[u] + 1
			q.push(i)
		}
	}

	// print distance
	for i, d := range distance {
		fmt.Printf("%d %d\n", i+1, d)
	}
}

func main() {
	adj := makeAdjList()
	bfs(adj, 0)
}

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

struct node {
	std::vector<int> child;
	int distance;
};

int main() {
	int node_num;

	std::cin >> node_num;

	std::vector<node> n(node_num);

	for (int i = 0; i < node_num; i++) {
		int num, to, node_val;
		std::cin >> node_val >> num;
		for (int j = 0; j < num; j++) {
			std::cin >> to;
			n[node_val - 1].child.push_back(to);
		}
		n[i].distance = -1;
	}

	//???????????????????????¢0
	n[0].distance = 0;
	std::queue<int> q;
	int dist = 1;
	q.push(1);
	while(q.size() != 0){
		int num = q.front();
		q.pop();
		for (auto it = n[num - 1].child.begin(); it != n[num - 1].child.end(); it++) {
			q.push(*it);
			if (n[*it - 1].distance > dist || n[*it - 1].distance == -1) {
				n[*it - 1].distance = dist;
			}
		}
		dist++;
	}

	for (int i = 0; i < node_num; i++) {
		std::cout << i + 1 << " " << n[i].distance << std::endl;
	}
	return 0;
}

C++: #include <cmath>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <climits>
#include <map>
#include <list>
#include <stack>
#include <queue>
#include <vector>
#include <string>
#include <sstream>
#include <fstream>
#include <iostream>
#include <algorithm>
using namespace std;

int n ,dist[128];
bool rel[128][128];

int main() {
	scanf("%d", &n);
	
	for(int i = 1; i <= n; i++){
		int u, k;
		scanf("%d %d", &u, &k);
		
		dist[u] = INT_MAX;
		for(int j = 1; j <= n; j++){
			rel[u][j] = false;
		}
		while(k--){
			int v;
			scanf("%d", &v);
			rel[u][v] = true;
		}
	}
	
	queue<int> visit;
	visit.push(1);
	dist[1] = 0;
	
	while(visit.size()){
		for(int i = 1; i <= n; i++){
			if(rel[visit.front()][i] && 1 + dist[visit.front()] < dist[i]){
				visit.push(i);
				dist[i] = 1 + dist[visit.front()];
			}
		}
		visit.pop();
	}
	
	for(int i = 1; i <= n; i++){
		printf("%d %d\n", i, dist[i]);
	}
	return 0;
}

C++: #include <bits/stdc++.h> 

#define int long long
#define double long double

#define REP(i, b) for(int i = 0; i < (b); i++)
#define REPS(i, b) for(int i = 1; i <= (b); i++)
#define ALL(v) (v).begin(), (v).end()

#define fi first
#define se second
#define pb push_back
#define mp make_pair

using namespace std;

using pi = pair<int, int>;
using vi = vector<int>;
using vd = vector<double>;
using vs = vector<string>;
using vb = vector<bool>;
using vpi = vector<pi>;
using vvi = vector<vi>;
using vvb = vector<vb>;

const int INF = 1e16;
const int MOD = 1e9+7;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

signed main()
{
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(10);

    int n; cin >> n;
    vvi G(n, vi(n));
    vi d(n, INF); d[0] = 0;
    REP(i, n)
    {
        int u, k; cin >> u >> k; u--;
        REP(j, k)
        {
            int v; cin >> v; v--;
            G[u][v] = 1;
        }
    }

    REP(k, n)
    {
        REP(i, n)
        {
            REP(j, n)
            {
                if(G[i][j] == 1) chmin(d[j], d[i]+1);
            }
        }
    }
    REP(i, n) cout << i+1 << " " << ((d[i] == INF) ? -1 : d[i]) << endl;
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <utility>
#include <queue>
#include <stack>
#include <string>
#include <climits>
using namespace std;

#define MAX_N 101

int n;
vector<vector<int> > A(MAX_N, vector<int>(MAX_N, 0));
queue<int> Q;
int d[MAX_N];

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

C++: #include<bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i) 
#define PI acos(-1)

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

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

    int n;
    cin>>n;
    vector<vector<int>> adj(n);
    rep(i, n) {
        int u, k, v;
        cin>>u>>k; u--;
        rep(j, k) {
            cin>>v; v--;
            adj[u].push_back(v);
        }
    }

    vector<int> dist(n, -1);
    queue<P> q;
    q.push(P(0, 0));
    while (!q.empty()) {
        P p = q.front(); q.pop();
        int v = p.first;
        if (dist[v] != -1) continue;
        int d = p.second;
        dist[v] = d;
        for (auto e : adj[v]) {
            q.push(P(e, d + 1));
        }
    }
    rep(i, n) cout<<i + 1<<" "<<dist[i]<<endl;
}

C++: #include <cstdio>
#include <queue>
#include <vector>

int main()
{
  int n;
  scanf("%d", &n);

  std::vector<std::vector<int>> graph;
  graph.resize(n);
  for (int i = 0; i < n; ++i)
  {
    int u, k, v;
    scanf("%d%d", &u, &k);
    for (int j = 0; j < k; ++j)
    {
      scanf("%d", &v);
      graph[u - 1].push_back(v - 1);
    }
  }

  std::queue<int> vertex;
  vertex.push(0);
  int current_distance = 0;

  int distances[n];
  for (int i = 0; i < n; ++i)
    distances[i] = -1;

  while (vertex.size() > 0)
  {
    int s = vertex.size();

    // Loop for current depth
    for (int i = 0; i < s; ++i)
    {
      int id = vertex.front();
      vertex.pop();

      if (distances[id] == -1)
        distances[id] = current_distance;

      std::vector<int>::const_iterator itr;
      for (itr = graph[id].begin(); itr != graph[id].end(); ++itr)
        vertex.push(*itr);
    }

    ++current_distance;
  }

  for (int i = 0; i < n; ++i)
    printf("%d %d\n", i + 1, distances[i]);

  return 0;
}