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<bits/stdc++.h>
using namespace std;
const int maxn=100+10;
int n,dis[maxn],vis[maxn];
vector<int>G[maxn];
void bfs(){
    memset(dis,0,sizeof dis);
    memset(vis,0,sizeof vis);
    queue<int>que;
    que.push(1);vis[1]=1;dis[1]=0;
    while(!que.empty()){
        int cur=que.front();que.pop();
        for(auto i:G[cur]){
            if(!vis[i]){
                que.push(i);
                dis[i]=dis[cur]+1;
                vis[i]=1;
            }
        }
    }
}
int main()
{
    cin>>n;
    for(int i=0;i<n;i++){
        int u,k;cin>>u>>k;
        for(int j=0;j<k;j++){
            int v;cin>>v;
            G[u].push_back(v);
        }
    }
    bfs();
    for(int i=1;i<=n;i++) if(!vis[i]) dis[i]=-1;//在bfs完以后还没到达的点到1点的距离设置为-1
    for(int i=1;i<=n;i++) cout<<i<<" "<<dis[i]<<"\n";
}
/*
4
1 2 2 4
2 1 4
3 0
4 1 3
*/

C++: #include <cassert>
#include <algorithm>
#include <iostream>
#include <vector>
#include <string>

class TVertex
{
    int FIndex;
    std::vector<TVertex*> FList;
    int FDistance;

public:
    TVertex(int Index)
     : FIndex(Index), FDistance(-1)
    {}
    void AddPath(TVertex* Vertex)
    {
        FList.push_back(Vertex);
    }
    void PrintDistance(std::ostream& out)const
    {
        out << FIndex << " " << FDistance << std::endl;
    }
    void BreadthFirstSearch(int Distance)
    {
        if(FDistance <= Distance && FDistance != -1) return;
        FDistance = Distance++;
        for(std::vector<TVertex*>::iterator It = FList.begin(); It != FList.end(); ++It){
            TVertex* V = *It;
            V->BreadthFirstSearch(Distance);
        }
    }
};
class TGraph
{
    std::vector<TVertex*> FTable;
    void Init(int n)
    {
        assert(n > 0);
        FTable.resize(n);
        for(int i = 0; i < n; ++i){
            FTable[i] = new TVertex(i);
        }
    }
public:
    TGraph(int n)
    {
        Init(n+1);
    }
    
    void SetupVertex(std::istream& in)
    {
        int Index;
        in >> Index;
        assert(Index >= 1);
        assert(Index <= FTable.size());
        int k;
        in >> k;
        for(int i = 0; i < k; ++i){
            int v;
            in >> v;
            FTable[Index]->AddPath(FTable[v]);
        }
    }
    void BreadthFirstSearch()
    {
        FTable[1]->BreadthFirstSearch(0);
    }
    void PrintDistance(std::ostream& out)
    {
        for(int i = 1; i < FTable.size(); ++i){
            FTable[i]->PrintDistance(out);
        }
    }
};

int main()
{
    int n;
    std::cin >> n;
    TGraph Graph(n);
    for(int i = 0; i < n; ++i){
        Graph.SetupVertex(std::cin);
    }
    Graph.BreadthFirstSearch();
    Graph.PrintDistance(std::cout);
    return 0;
    
}

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

using namespace std;

typedef pair<int, int> P;
typedef long long int LL;

vector<int> v[101];
vector<int> dist;
queue<int> q;

int bfs() {
    dist[1] = 0;
    q.push(1);

    while (!q.empty()) {
        int c = q.front();
        q.pop();
        for (int i = 0; i < v[c].size(); i++) {
            if (dist[v[c][i]] == -1) {
                dist[v[c][i]] = dist[c] + 1;
                q.push(v[c][i]);
            }
        }
    }
}

int main() {
    int n;
    cin >> n;
    dist.resize(n + 1, -1);

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

    bfs();

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

    return 0;
}

C++: #include <iostream>
#include <fstream>
#include <cstdlib>
#include <math.h>
#include <utility>
#include <algorithm>
#include <functional>
#include <vector>
#include <numeric>
#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using vi = vector<int>;
using vll = vector<ll>;
using vb = vector<bool>;
using qi = queue<int>;
using Graph = vector<vector<int>>;

#define FOR(i, a, b) for (int i = a; i < (b); i++)
#define REP(i,n) for(int i=0;i<n;i++)

qi que;
vi dist;

void bfs(Graph &G) {
    while (!que.empty()) {
        int v = que.front();
        que.pop();

        for(int next_v : G[v]) {
            if (dist[next_v] != -1) continue;
            que.push(next_v);
            dist[next_v] = dist[v] + 1;
        }
    }
}

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

    int n; cin >> n;
    Graph G(n);
    REP(i, n) {
        int u; cin >> u;
        int k; cin >> k;
        REP(j, k) {
            int v; cin >> v;
            G[i].push_back(v-1);
        }
    }

    que.push(0);
    dist.assign(n, -1);
    dist[0] = 0;
    bfs(G);

    REP(i, n) {
        cout << (i+1) << " " << dist[i] << "\n";
    }
}

C++: #include <stdio.h>
#include <iostream>
using namespace std;

class Adjl{
private:
	int u;
	int k;
	Adjl **next;
public:
	Adjl(int u);
	~Adjl(){ if (next != NULL) delete[] next; }
	void setV(int k, Adjl *vk);
	int breadthFirstSearch(int id);
	void print(int id);
};

Adjl::Adjl(int u)
{
	this->u = u;
	k = 0;
	next = NULL;
}

void Adjl::setV(int k, Adjl *vk)
{
	if (this->k == 0) next = new Adjl*[k];
	next[this->k] = vk;
	(this->k)++;
}

int Adjl::breadthFirstSearch(int id)
{
	if (id == u) return 0;
	int d_min = -1;
	for (int i = 0; i < k; i++) {
		int d = next[i]->breadthFirstSearch(id);
		if (d == -1) continue;
		if (d_min == -1) d_min = d + 1;
		else d_min = min(d + 1, d_min);
	}
	return d_min;
}

void Adjl::print(int id)
{
	cout << id << " " << breadthFirstSearch(id) << endl;
}

int main(void)
{
	int n;
	cin >> n;
	
	Adjl **adjl = new Adjl*[n];
	int check[100] = {0};

	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		if (check[i] == 0) {
			adjl[i] = new Adjl(u);
			check[i] = 1;
		}
		check[i] = 1;
		for (int j = 0; j < k; j++) {
			int vk;
			cin >> vk;
			if (check[vk - 1] == 0) {
				adjl[vk - 1] = new Adjl(vk);
				check[vk - 1] = 1;
			}
			adjl[i]->setV(k, adjl[vk - 1]);
		}
	}

	for (int i = 1; i <= n; i++) {
		adjl[0]->print(i);
	}

	delete[] adjl;
	return 0;
}