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<algorithm>
#include<vector>
#include<cassert>
#include<cstdio>
#include<queue>

using namespace std;

int N, G[100][100], V[100], D[100];//G:２頂点,V:次数,D:距離

void bfs(int src){
	queue<int> Q;
	Q.push(src);
	fill(D, D + N, -1);
	D[src] = 0;
	while (!Q.empty()){
		int cur = Q.front();
		Q.pop();
		for (int k = 0; k < N; k++){
			if (G[cur][k] == 1 && D[k] == -1){
				D[k] = D[cur] + 1;
				Q.push(k);
			}
		}
	}
	for (int l = 0; l < N; l++){
		cerr << l + 1 << " " << D[l] << endl;
	}
}

int main(){
	scanf_s("%d", &N);
	int id, c;
	for (int i = 0; i < N; i++){
		scanf_s("%d", &id); id--;//配列は0から始まるので、頂点番号を-1して考える。
		scanf_s("%d", V + id);
		for (int j = 0; j < V[id]; j++){
			scanf_s("%d", &c); c--;//配列は0から始まるので、頂点番号を-1して考える。
			G[id][c] = 1;
		}
	}//データの読み込み完了。
	bfs(0);
}

C++: #include <bits/stdc++.h>
using namespace std;
#ifdef ENABLE_DEBUG_OUTPUT
#define DEBUG_LOG(s) cout << s << endl;
#else
#define DEBUG_LOG(s) void();
#endif

void bfs(const int start, vector<vector<int>>& graph,
         vector<int>& dist) {
    queue<int> q; q.push(start); dist[start] = 0;
    while(not q.empty()) {
        auto p = q.front(); q.pop();

        for (auto elm : graph[p]) {
            if(dist[elm] < 0 or dist[elm] > dist[p] + 1) {
                dist[elm] = dist[p] + 1;
                q.push(elm);
            }
        }
    }
}

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

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

    vector<int> dist(n, -1);
    bfs(0, g, dist);

    for (auto i = 0; i < n; i++) cout << i+1 << " " << dist[i] << endl;
    return 0;
}

C++: #include <iostream>
#include <queue>
 
using namespace std;
 
int D[110]={0};
void bfs(int src,int n,int g[110][110]){
 
queue<int> Q;
Q.push(src);
D[src]=0;
while (! Q.empty()){
    int cur =Q.front();
    Q.pop();
    for(int r=0;r<n;r++){
        if (g[cur][r]==1&&D[r]==0){
            D[r]=D[cur]+1;
            Q.push(r);
        }
    }
}
}
int main() {
int n,g[110][110]={0};
cin>>n;
int j,num,t;
for(int k=0;k<n;k++){
cin>>j>>num;
for(int kk=0;kk<num;kk++){
    cin>>t;
    g[k][t-1]=1;
}
}
bfs(0,n,g);

for(int a=0;a<n;a++){
    if(D[a]!=0){
    cout<<a+1<<" "<<D[a]<<endl;
}
else{
	if (a!=0){
    cout<<a+1<<" -1"<<endl;
}
	else{
		cout<<a+1<<" 0"<<endl;
	}
}
}
    return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;
const int maxn=110;
int table[maxn][maxn];
int d[maxn],vis[maxn];
int n;

void bfs(){
    queue<int> q;
    q.push(1);
    d[1]=0;
    vis[1]=1;
    while(!q.empty()){
        int v=q.front();
        q.pop();
        for(int i=1;i<=n;i++){
            if(!vis[i] && table[v][i]){
                vis[i]=1;
                d[i]=d[v]+1;
                q.push(i);
            }
        }
    }
}
int main(){
    int u,k,num;
    cin>>n;
    for(int i=1;i<=n;i++){
        d[i]=-1;
        vis[i]=0;
        cin>>u>>k;
        while(k--){
            cin>>num;
            table[u][num]=1;
        }
    }
    bfs();
    for(int i=1;i<=n;i++)
        cout<<i<<" "<<d[i]<<endl;

}

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

int n, dd[101], f[101], tmap[101][101];
int color[101], t = 0;
queue<int> Q;


void a(){
	while (!Q.empty()){
		int d = Q.front();
		Q.pop();
		for (int i = 1; i <= n; i++){
			if (color[i] == 0 && tmap[d][i] == 1){
				Q.push(i);
				color[i] = 1;
				dd[i] = dd[d] + 1;
			}
		}
	}
}


int main(){
	cin >> n;
	for (int i = 0; i < 100; i++){
		f[i] = color[i] = 0;
		dd[i] = -1;
		for (int j = 0; j < 100; j++){
			tmap[i][j] = 0;
		}
	}

	int u, k, v;

	for (int i = 0; i < n; i++){
		cin >> u >> k;
		for (int j = 0; j < k; j++){
			cin >> v;
			tmap[u][v] = 1;
		}
	}
	color[1] = 1;
	Q.push(1);
	dd[1] = t;
	a();
	for (int i = 1; i <= n; i++){
		cout << i << " " << dd[i] << endl;
	}
	return 0;
}

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

#define REP(i,n) for(int i=0;i<(n);i++)
#define REAP(i,a,n) for(int i=(a);i<(n);i++)
#define YES cout<<"Yes"<<endl
#define NO cout<<"No"<<endl
#define fr first
#define sc second
#define pb push_back
#define All(v) v.begin(),v.end()
typedef long long ll;

int table[101][101];

void init(){
    REP(i,101){
        REP(j,101){
            table[i][j]=1e9;
            if(i==j)table[i][j]=0;
        }
    }
}

int main(){
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    init();
    int u,k,v;
    REP(i,n){
        cin >> u >> k;
        REP(j,k){
            cin >> v;
            table[u-1][v-1]=1;
        }
    }

    REP(i,n){
        REP(j,n){
            REP(k,n){
                table[i][j]=min(table[i][j],table[i][k]+table[k][j]);
            }
        }
    }
    REP(i,n){
        cout << i+1 << " " << ((table[0][i]<n)?table[0][i]:-1);
        cout << endl;
    }
}

C++: #include <iostream>
#include <queue>
#define INFTY -10000000
using namespace std;



int a[124][124] = {{}};
int d[124] = {};
int n;
void bfs(int k){
  queue <int> q;
  q.push(k);
  int u;


  while(!q.empty()){
    u = q.front(); q.pop();
    for(int v = 0;v < n;v++){
      if(a[u][v] == 0) continue;
      if(d[v] == INFTY) {
        d[v] = d[u] + 1;
        //cout << v << " " << d[v] << endl;
      }
      q.push(v);
    }

  }
}

int main(){

  int u,k,x;
  cin >> n;

d[0] = 0;
for(int i = 1; i < n;i++) d[i] = INFTY;

  for(int i = 0;i < n;i++){
    cin >> u >> k;
    for(int j = 0;j < k;j++){
      cin >> x;
      a[u - 1][x - 1] = 1;
    }
  }

  bfs(0);

  for(int i = 0;i < n;i++){
    cout << i + 1 << " " << d[i] << endl;
  }
}