Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

func stringifyArray(arr []int) string {
	return strings.TrimRight(fmt.Sprintf("%+v", arr)[1:], "]")
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, &g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

func fillDistancesByBreadthFirstSearch(g *DirectedGraph, startNode *DirectedGraphNode) {
	startNode.visited = true
	startNode.d = 0

	queue := Queue{}
	queue.enqueue(startNode)
	for !queue.isEmpty() {
		u := queue.dequeue().node
		for _, adjacent := range u.adjacents {
			if !adjacent.visited {
				adjacent.visited = true
				adjacent.d = u.d + 1
				adjacent.parent = u
				queue.enqueue(adjacent)
			}
		}
		u.visited = true
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	// fmt.Println(g)
	fillDistancesByBreadthFirstSearch(g, &g.nodes[1])
	// fmt.Println(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		distance := node.d
		if distance == infty {
			distance = -1
		}
		fmt.Println(node.key, distance)
	}
}

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;
}