Go: package main

import (
	"container/list"
	"fmt"
	"bufio"
	"os"
	"strconv"
)

const (
	N   = 100
	INF = 1 << 21
)

var (
	n        int
	adj      [N][N]int
	distance [N]int
)

func BFS(start int) {
	q := list.New()
	q.PushBack(start)
	for i := 0; i < n; i++ {
		distance[i] = INF
	}
	distance[start] = 0
	u := 0
	for q.Len() != 0 {
		u = q.Remove(q.Front()).(int)
		for v := 0; v < n; v++ {
			if adj[u][v] == 0 {
				continue
			}
			if distance[v] != INF {
				continue
			}
			distance[v] = distance[u] + 1
			q.PushBack(v)
		}
	}
	for i := 0; i < n; i++ {
		var d int
		if distance[i] == INF {
			d = -1
		} else {
			d = distance[i]
		}
		fmt.Printf("%d %d\n", i+1, d)
	}
}

func main() {
	var u, k, v int
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	scanner.Scan()
	n, _ = strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			adj[i][j] = 0
		}
	}
	for i := 0; i < n; i++ {
		scanner.Scan()
		u, _ = strconv.Atoi(scanner.Text())
		u -= 1
		scanner.Scan()
		k, _ = strconv.Atoi(scanner.Text())
		for j := 0; j < k; j++ {
			scanner.Scan()
			v, _ = strconv.Atoi(scanner.Text())
			v -= 1
			adj[u][v] = 1
		}
	}
	BFS(0)
}

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

int n;
bool A[105][105];
int D[105];

void bfs(int src){
    queue<int> Q;
    Q.push(src);
    D[src] = 0;
    while(!Q.empty()){
        int cur = Q.front();
        Q.pop();
        for(int dst=0; dst<105; dst++){
            if(A[cur][dst]==1 && D[dst]==-1){
                D[dst]=D[cur]+1;
                Q.push(dst);
            }
        }
        
    }
}

int main(int argc, const char * argv[]) {
    for(int i=0; i<105; i++){
        for(int j=0; j<105; j++){
            A[i][j] = 0;
        }
    }
    cin >> n;
    for(int i=0; i<n; i++){
        int u;
        int k;
        cin >> u >> k;
        u--;
        for(int j=0; j<k; j++){
            int v;
            cin >> v;
            v--;
            A[u][v] = 1;
        }
    }
    for(int i=0; i<105; i++){
        D[i] = -1;
    }
    bfs(0);
    for(int i=0; i<n; i++){
        cout << i+1 << " " << D[i] << endl;
    }
    return 0;
}

C++: #if 0
IDが1から始まることをどのように扱うかを最初にしっかり定義していなかったせいで時間がかかってしまった。
#endif

#include <iostream>
#include <vector>
#include <queue>
#include <map>
using namespace std;

map<int, vector<int>> init(int N)
{
    map<int, vector<int>> P;
    for (int i = 0; i < N; i++)
    {
        int id, dataNum;
        cin >> id >> dataNum;
        vector<int> temp;
        for (int j = 0; j < dataNum; j++)
        {
            int tempNode;
            cin >> tempNode;
            temp.push_back(tempNode);
        }
        P[id - 1] = temp; // P[i] = 隣接ノード
    }
    return P;
}

int main()
{
    int N;
    cin >> N;
    map<int, vector<int>> P = init(N);
    int distance[N];
    for (int i = 0; i < N; i++)
    {
        distance[i] = -1;
    }
    distance[0] = 0;
    queue<int> Q = queue<int>({0});
    while (!Q.empty())
    {
        int cur = Q.front(); // 現在地
        Q.pop();
        for (int itr = 0; itr < P[cur].size(); itr++)
        {
            int dst = P[cur][itr] - 1;
            if (distance[dst] == -1)
            {
                distance[dst] = distance[cur] + 1;
                Q.push(dst);
            }
        }
    }
    for (int i = 0; i < N; i++)
    {
        cout << i + 1 << " " << distance[i] << endl;
    }
}

C++: #include <iostream>
#include <string>
#include <sstream>
#include <list>
#include <stack>
#include <queue>
#include <algorithm>
#include <utility>
#include <vector>
#include <map>
#include <bitset>
#include <cstring>
#include <cstdio>
#include <cmath>

using namespace std;

struct dd{
    int id,f;
    dd(){
        id=0;
        f=0;
    }
    dd(int a,int b){
        id=a;
        f=b;
    }
};
bool data[101][101]={};

void f1(dd*,int,int&,int);

int main()
{
    int N,M,num1,num2;
    dd ddata[101]={};
    cin>>N;
    for(int i=0;i<N;i++){
        cin>>num1;
        cin>>M;
        for(int j=0;j<M;j++){
            cin>>num2;
            data[num1][num2]=true;
        }
    }
    int time=1;
    queue<dd> que;
    bool vd[101]={};
    que.push(dd(1,0));
    int val[101]={};
    vd[1]=true;
    for(dd ddata=que.front();!que.empty();que.pop(),ddata=que.front()){
        val[ddata.id]=ddata.f;
        for(int i=1;i<=N;i++){
            if(data[ddata.id][i]&&!vd[i]){
                vd[i]=true;
                que.push(dd(i,ddata.f+1));
            }
        }
    }
    for(int i=1;i<=N;i++){
        cout<<i<<' '<<val[i];
        cout<<endl;
    }
}

C++: #include <iostream>
#include <vector>
#include <unordered_map>
#include <set>
#include <queue>
//#include "../cxx-prettyprint/prettyprint.hpp"


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

    std::unordered_map<int, std::vector<int>> Adj(n);

    for (int i = 0; i < n; i ++) {
        int u, k;
        std::cin >> u >> k;
        std::vector<int> V(k);
        for (int& v : V) {
            std::cin >> v;
        }
        Adj[u] = V;
    }

    std::set<int> nodes_unvisited;
    std::unordered_map<int, int> distances;
    for (int i = 1; i <= n; i ++) {
        nodes_unvisited.insert(i);
        distances[i] = -1;
    }

    nodes_unvisited.erase(1);
    distances[1] = 0;
    std::queue<int> queue;
    queue.push(1);

    while (!queue.empty()) {
        int u = queue.front();
        queue.pop();
        for (int v : Adj[u]) {
            if (nodes_unvisited.find(v) != nodes_unvisited.end()) {
                nodes_unvisited.erase(v);
                distances[v] = distances[u] + 1;
                queue.push(v);
            }
        }
    }

    for (int i = 1; i <= n; i ++) {
        std::cout << i << " " << distances[i] << std::endl;
    }
}

C++: #include<bits/stdc++.h>
using namespace std;
#define clr(a,b) memset(a,b,sizeof(a))
int n;
int v,k,ttm;
vector<int> graph[105];
int dis[105];//到其他点的距离
int vis[105];//纪律顶点是否被访问
void bfs(int u)
{
    queue<int> qu;
    qu.push(u);
    dis[u]=0;
    vis[u]=1;
    while(!qu.empty())
    {
        int v=qu.front();qu.pop();
        for(int i:graph[v])
        {
            if(vis[i]){continue;}
            vis[i]=1;qu.push(i);
            dis[i]=dis[v]+1;
        }
    }
}
int main()
{
    clr(vis,0);
    cin>>n;
    for(int i=0;i<n;++i)
    {
        cin>>v>>k;
        while(k--)
        {
            cin>>ttm;
            graph[v].push_back(ttm);//连接的点
        }
    }
    bfs(1);
     cout<<1<<" "<<dis[1]<<endl;
    for(int i=1;i<=n;++i)
    {
         cout<<i<<" "<<(dis[i]?dis[i]:-1)<<endl;
    }
    return 0;
}

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

using namespace std;

struct Info{
	Info(){m_node = m_distance = 0;}
	Info(int node,int distance){
		m_node = node;
		m_distance = distance;
	}
	int m_node,m_distance;
};

class InfoQueue{
public:
	InfoQueue(){
		info = new Info[10000];
		num_of_data = head = tail = 0;
	}
	bool isEmpty(){
		return num_of_data == 0;
	}
	void enqueue(Info data){
		info[tail] = data;
		tail = (tail+1)%10000;
		num_of_data++;
	}
	Info dequeue(){
		Info ret = info[head];
		head = (head+1)%10000;
		num_of_data--;
		return ret;
	}
private:
	Info* info;
	int head,tail,num_of_data;
};


int main(){

	int n,row,col,num;
	scanf("%d",&n);

	int table[n+1][n+1];
	int check_table[n+1];

	for(int i=1;i<=n;i++){
		check_table[i] = -1;
		for(int k=1;k<=n;k++)table[i][k] = 0;
	}

	for(int i=1;i<=n;i++){
		scanf("%d %d",&row,&num);
		for(int k=1;k<=num;k++){
			scanf("%d",&col);
			table[row][col]=1;
		}
	}

	check_table[1] = 0;

	InfoQueue Q;
	Q.enqueue(Info(1,0));

	Info tmp;
	while(!Q.isEmpty()){
		tmp = Q.dequeue();
		for(int i=1;i<=n;i++){
			if(table[tmp.m_node][i]==1 && check_table[i] == -1){
				check_table[i] = tmp.m_distance+1;
				Q.enqueue(Info(i,tmp.m_distance+1));
			}
		}
	}

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

    return 0;
}