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 <stack>
#include <queue>

using namespace std;

static const int N = 100;
static const int NEW = 0;
static const int VISITING = 1;
static const int OLD = 2;

int n, m[N][N] = {0}, t;
int color[N] = { 0 }, t1[N] = { 0 }, t2[N] = {0};

void getMatrix()
{
	int u, v, k;
	cin >> n;
	for (int i = 0; i < n; ++i)
	{
		cin >> u >> k;
		for (int j = 0; j < k; ++j)
		{
			cin >> v;
			m[u-1][v-1] = 1;
		}
	}
}

int nxt(int idx)
{
	for (int i = 0; i < n; ++i)
	{
		if (1 == m[idx][i] && color[i] == NEW)
			return i;
	}
	return -1;
}

void dfs_visit(int idx)
{
	stack<int> s;
	s.push(idx);
	color[idx] = VISITING;
	t1[idx] = t++;


	while (!s.empty())
	{
		int u = s.top();
		int v = nxt(u);
		if (-1 != v)
		{
			color[v] = VISITING;
			t1[v] = t++;
			s.push(v);
		}
		else
		{
			s.pop();
			color[u] = OLD;
			t2[u] = t++;
		}
	}
}

void dfs()
{
	t = 1;

	for (int i = 0; i < n; ++i)
		color[i] = NEW;

	for (int i = 0; i < n; ++i)
	{
		if (color[i] == NEW)
			dfs_visit(i);
	}

	for (int i = 0; i < n; ++i)
	{
		cout << i + 1 << " " << t1[i] << " " << t2[i] << endl;
	}
}

int dist[N];

void bfs(int idx)
{
	queue<int> q;
	q.push(idx);

	for (int i = 0; i < n; ++i)
		dist[i] = INT_MAX;
	dist[idx] = 0;

	int u;
	while (!q.empty())
	{
		u = q.front(); q.pop();
		for (int i = 0; i < n; ++i)
		{
			if (m[u][i] == 0) continue;
			if (dist[i] != INT_MAX) continue;
			dist[i] = dist[u] + 1;
			q.push(i);
		}
	}
	for (int i = 0; i < n; ++i)
	{
		cout << i + 1 << " " <<( (dist[i] == INT_MAX) ? (-1) : dist[i]) << endl;
	}
}


int main()
{
	getMatrix();
	bfs(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() {
  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 <cstdio>
#include <vector>
#include <queue>
using namespace std;

const int maxn = 100;
vector<int> G[maxn + 5];
//int book[maxn + 5][maxn + 5];
int n;
int far[maxn + 5];


int bfs(int vertex) {
    queue<int> q;
    int book[maxn + 5] = {};
    q.push(vertex);
    book[vertex] = 1;
    int min = 0;
    if(vertex == 1) return 0;

    while(!q.empty()) {
        int now = q.front();
        q.pop();

        int len = G[now].size();
        for(int i = 0; i < len; i++) {
            if(book[G[now][i]]) continue;

            if(G[now][i] == 1) return min + 1;

            book[G[now][i]] = 1;
            q.push(G[now][i]);
        }
        min++;
    }
    return -1;
}



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

    for(int i = 1; i <= n; i++) {
        int num;
        scanf("%d", &num);
        int count;
        scanf("%d", &count);


        while(count--) {
            int temp; scanf("%d", &temp);
            G[num].push_back(temp);
            G[temp].push_back(num);
        }
    }

    for(int i = 1; i <= n; i++) {
        far[i] = bfs(i);
    }

    for(int i = 1; i <= n; i++) {
        printf("%d %d\n", i, far[i]);
    }

    return 0;
}

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


//使用队列实现广度优先搜索

using namespace std;

static const int N=100;
static const int INFTY=(1<<21);

/**
 * M 邻接矩阵
 * queue 记录下一个待访问顶点的队列
 * 将七点s到各顶点的最短距离记录在d[i]中
 */

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?d[i]:(-1))<<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 i=0;i<n;i++){
            cin>>v;
            v--;
            M[u][v]=1;
        }
    }
    
    bfs(0);
    return 0;
}

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

int time, n;
int d[100], color[100];
int M[100][100];

void bfs(int s) {
    std::queue<int> Q;
    
    for (int i=0; i<100; i++){
        color[i] = 0;
        d[i] = -1;
    }
    
    color[s] = 1;
    d[s] = 0;
    Q.push(s);
    while (!Q.empty()) {
        int u = Q.front(); Q.pop();
        for (int i=0; i<n; i++) {
            if(M[u][i] && color[i] == 0) {
                color[i] = 1;
                d[i] = d[u]+1;
                Q.push(i);
            }
        }
        color[u] = 2;
    }
}

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