Go: package main

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

type AdjacentList struct {
	matrix [][]int
}

func NewEmptyAdjacentList(dim int) *AdjacentList {
	matrix := make([][]int, dim)
	for i := 0; i < dim; i++ {
		matrix[i] = make([]int, dim)
	}
	return &AdjacentList{matrix: matrix}
}

func (al *AdjacentList) set(node int, adjacent int) {
	al.matrix[node-1][adjacent-1] = 1
}

func (al *AdjacentList) findAdjacentsFor(node int) []int {
	adjacents := []int{}
	for i, v := range al.matrix[node-1] {
		if v == 1 {
			adjacents = append(adjacents, i+1)
		}
	}
	return adjacents
}

type DistanceList struct {
	list []int
}

func NewDistanceList(dim int) *DistanceList {
	list := make([]int, dim)
	for i := 0; i < dim; i++ {
		list[i] = -1
	}
	return &DistanceList{list: list}
}

func (dl *DistanceList) set(node int, distance int) {
	dl.list[node-1] = distance
}

func (dl *DistanceList) get(node int) int {
	return dl.list[node-1]
}

func (dl *DistanceList) isVisited(node int) bool {
	return dl.list[node-1] >= 0
}

type Position struct {
	node     int
	distance int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	dim, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	al := NewEmptyAdjacentList(dim)

	for i := 1; i <= dim; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}

		adjacentNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		for j := 0; j < adjacentNum; j++ {
			adjacent, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			al.set(node, adjacent)
		}
	}

	dl := NewDistanceList(dim)

	bfs(al, dl)

	for i := 1; i <= dim; i++ {
		fmt.Printf("%d %d\n", i, dl.get(i))
	}
}

func bfs(al *AdjacentList, dl *DistanceList) {
	stack := []Position{Position{node: 1, distance: 0}}
	for len(stack) > 0 {
		currentPosition := stack[0]
		stack = stack[1:]
		if !dl.isVisited(currentPosition.node) {
			dl.set(currentPosition.node, currentPosition.distance)
		}
		for _, v := range al.findAdjacentsFor(currentPosition.node) {
			stack = append(stack, Position{node: v, distance: currentPosition.distance + 1})
		}
	}
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: //http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_C&lang=ja
//幅優先探索
#include <bits/stdc++.h>
#if LOCAL
#include "dump.hpp"
#else
#define dump(...)
#endif
using namespace std;
using ll=long long;
#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
template<class T>bool chmax(T &a, const T &b) {if (a<b) { a=b; return 1; } return 0;}
template<class T>bool chmin(T &a, const T &b) {if (b<a) { a=b; return 1; } return 0;}

template< typename T >
struct edge {
	int src, to;
	T cost;
	edge(int _to, T _cost) : src(-1), to(_to), cost(_cost) {}
	edge(int _src, int _to, T _cost) : src(_src), to(_to), cost(_cost) {}
	edge &operator=(const int &x) {
		to = x;
		return *this;
	}
	operator int() const { return to; }
};

template< typename T>
struct node {
	vector<edge<T>> edges;
    ll dist=-1;
};

template< typename T >
using Edges = vector< edge< T > >;
template< typename T >
using WeightedGraph = vector< node< T > >;
using UnWeightedGraph = vector< vector< int > >;
template< typename T >
using Matrix = vector< vector< T > >;

int main() {
#if LOCAL&01
    std::ifstream in("./test/sample-1.in");
    //std::ifstream in("./input.txt");
    std::cin.rdbuf(in.rdbuf());
#else
    cin.tie(0);
    ios::sync_with_stdio(false);
#endif
    ll n; cin>>n;
    WeightedGraph<ll> graph(n+1);
    FOR(i,1,n+1){
        ll u,k; cin>>u>>k;
        REP(j,k){
            ll v; cin>>v;
            graph.at(u).edges.emplace_back(v,1);
        }
    }

    queue<ll> st;
    st.push(1);
    graph.at(1).dist=0;
    while(not st.empty()){
        auto cn = st.front();
        st.pop();
        auto& node = graph.at(cn);
        for(const auto& nn:node.edges){
            if(graph.at(nn).dist>=0) continue;
            graph.at(nn).dist = node.dist + 1;
            st.push(nn.to);
        }
    }

    FOR(i,1,n+1){
        cout<<i<<" "<<graph.at(i).dist<<endl;
    }
    return 0;
}

C++: #include<cstdio>
#include<queue>
using namespace std;
static const int INF=(1<<21);
static const int MAXN=101;
int main()
{
	int n,m[MAXN][MAXN],i,j,u,k,v,l,o,c=1,t[MAXN],z=2;
	queue<int> q;
	bool used[MAXN]={};
	scanf("%d",&n);
	for(i=1;i<n+1;i++){
		for(j=1;j<n+1;j++){
			m[i][j]=INF;
		}
	}
	for(i=0;i<n;i++){
		scanf("%d %d",&u,&k);
		for(j=0;j<k;j++){
			scanf("%d",&v);
			m[u][v]=1;
		}
	}
	q.push(1);
	used[1]=true;
	t[1]=0;
	while(1){
		l=q.front();
		q.pop();
		o=0;
		for(i=1;i<n+1;i++){
			if(m[l][i]==1&&used[i]==false){
				q.push(i);
				used[i]=true;
				t[i]=c;
				o=1;
			}
		}
		if(o==1){
			c++;
		}
		if(q.empty()){
			z=0;
			for(i=1;i<n+1;i++){
				if(used[i]==false){
					q.push(i);
					z=1;
					used[i]=true;
					break;
				}
			}
		}
		if(z==0){
			break;
		}
		if(z==1){
			c++;
			z=2;
		}
	}
	for(i=1;i<n+1;i++){
		printf("%d %d\n",i,t[i]);
	}
	return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#define white 0
#define black -1
#define grey 1
using namespace std;
int a[110][110],n;
int d[110];
int color[110];

void bfs()
{
    memset(d,0,sizeof(d));
    queue<int> Q;
    d[1]=0;
    for(int i=1;i<=100;i++)
        color[i]=white;
    Q.push(1);
    while(!Q.empty())
    {
        int u=Q.front();
        Q.pop();
        for(int i=1;i<=n;i++)
        {
            if(a[u][i]==0)
                continue;
            if(d[i]!=0)
                continue;
                Q.push(i);
                color[i]=grey;
                d[i]=d[u]+1;
        }
    }
    for(int i=1;i<=n;i++)
   {
       printf("%d ",i);
       if(i==1) printf("%d",d[i]);
       else if(d[i]) printf("%d",d[i]);
       else printf("-1");
       printf("\n");
   }

}

int main()
{
   int key,d,x;
   memset(a,0,sizeof(a));
   scanf("%d",&n);
   for(int i=1;i<=n;i++)
   {
       scanf("%d%d",&key,&d);
       for(int j=1;j<=d;j++)
       {
        scanf("%d",&x);
        a[key][x]=1;
       }
   }
   bfs();
   return 0;
}

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

typedef long long ll;

int main()
{
    ll i,j;
    ll n;
    cin >> n;
    vector<vector<ll>> graph(n);
    for(i = 0;i < n;++i){
        ll u,k,v;
        cin >> u >> k;
        --u;
        for(j = 0;j < k;++j){
            cin >> v;
            --v;
            graph.at(u).push_back(v);
        }
    }
    queue<ll> que;
    vector<ll> visit(n,false);
    que.push(0);
    visit.at(0) = true;
    vector<ll> ans(n,-1);
    ans.at(0) = 0;
    while(!que.empty()){
        ll s = que.front();
        que.pop();
        ll dis = ans.at(s);
        for(i = 0;i < graph.at(s).size();++i){
            ll g = graph.at(s).at(i);
            if(visit.at(g)){
                continue;
            }
            ans.at(g) = dis+1;
            visit.at(g) = true;
            que.push(g);
        }
    }
    for(i = 0;i < n;++i){
        cout << i+1  << " " << ans.at(i) << endl;
    }
    return 0;
}