Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Queue struct {
	arr []int
}

func (q *Queue) push(v int) {
	q.arr = append(q.arr, v)
}

func (q *Queue) pop() int {
	res := q.arr[0]
	q.arr = q.arr[1:]
	return res
}

func (q *Queue) isEmpty() bool {
	return len(q.arr) == 0
}

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	var q Queue
	seen := make([]int, N)
	for i := 0; i < N; i++ {
		seen[i] = -1
	}
	var search func(cur int)
	search = func(cur int) {
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if seen[next] == -1 {
				q.push(next)
				seen[next] = seen[cur] + 1
			}
		}
	}
	q.push(0)
	seen[0] = 0
	for !q.isEmpty() {
		search(q.pop())
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i+1, seen[i])
	}
	wtr.Flush()
}

C++: #include <bits/stdc++.h>
using namespace std;
static const int N = 100;
static const int INFTY = (1<<21);

int n, M[N][N];
int d[N]; // 頂点0からの距離

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] && d[v] == INFTY) {
                // 未訪問
                q.push(v);
                d[v] = d[u] + 1;
            }
        }
    }

    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;
    // 初期化
    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 <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

#define WHITE 0
#define GRAY 1
#define BLACK 2

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

int n, M[N][N];
int color[N], d[N], f[N], tt;

// void dfs_visit(int u) {
//    color[u] = GRAY;
//    d[u] = ++tt;
//    rep(v, n) {
//       if (M[u][v] == 0) continue;

//       if(color[v] == WHITE) {
//          dfs_visit(v);
//       }
//    }
//    color[u] = BLACK;
//    f[u] = ++tt;
// }

// void dfs() {
//    int u;
//    for(u = 0; u < n; u ++) {
//       color[u] = WHITE;
//    }

//    for(u = 0; u < n; u ++) {
//       if(color[u] == WHITE) dfs_visit(u);
//    }

//    for(u =0; u<n;u++) {
//       printf("%d %d %d\n", u+1, d[u], f[u]);
//    }
// }

// void bfs_visit() {

// }

void bfs(int s) {
   queue<int> q;

   rep(i, n) {
      d[i] = INFTY;
      color[i] = WHITE;
   }

   q.push(s);
   d[s] = 0;

   while (!q.empty()) {
      int u = q.front(); q.pop();
      rep(v, n) {
         if (M[u][v] && color[v] == WHITE) {
            color[v] = GRAY;
            d[v] = d[u] + 1;
            q.push(v);
         }
      }
      color[u] = BLACK;
   }

   rep(i, n) {
      if(d[i] != INFTY) {
         cout << i+1 << " " << d[i] << endl;
      } else {
         cout << i+1 << " " << -1 << endl;
      }
   }
}

int main(){
   int u, k, v;
   cin>>n;

   // graphを0で初期化
   for(int i = 0; i < n; i ++) {
      for(int j = 0; j < n; j ++) {
         M[i][j] = 0;
      }
   }

   // 隣接リストを隣接行列に変換
   for(int i = 0; i < n; i ++) {
      scanf("%d %d", &u, &k);
      u--;
      for(int j = 0; j < k; j++) {
         scanf("%d", &v);
         v--;
         M[u][v] = 1;
      }
   }

   bfs(0);
   // dfs();
   return 0;
}

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

struct Tree
{
    int p, start, end, min;
    bool isSearched;
    vector<int> v;
};

void DFS( Tree* t, int a, int cnt )
{
    if( t[a].isSearched && t[a].min <= cnt )
        return;
    
    t[a].isSearched = true;

    if( t[a].min > cnt )
        t[a].min = cnt;

    cnt++;

    for( int i = 0; i < t[a].v.size(); i++ )
        DFS( t, t[a].v[i], cnt );
}


int main()
{
    int n, a, b, c;
    Tree t[101];

    for( int i = 0; i < 101; i++ )
    {
        t[i].p = -1;
        t[i].min = 1000;
        t[i].isSearched = false;
    }
    
    cin >> n;

    for( int i = 0; i < n; i++ )
    {
        cin >> a >> b;
        for( int j = 0; j < b; j++ )
        {
            cin >> c;
            t[a].v.push_back(c);
            t[c].p = a;
        }
    }

    int cnt = 0;
    DFS( t, 1, cnt );

    for( int i = 1; i <= n; i++ )
    {
        if( t[i].min == 1000 )
            cout << i << " " << -1 << endl;
        else
            cout << i << " " << t[i].min << endl;
    }
    return 0;
}

C++: #include<iostream>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i=0;i<n;i++)
using P = pair<int,int>;

/* 大文字を小文字に変換 */
char tolower(char c) {return (c + 0x20);}
/* 小文字を大文字に変換 */
char toupr(char c) {return (c - 0x20);}

// if('A'<=s[i] && s[i]<='Z') s[i] += 'a'-'A';

/*
string s = "abcdefg"
s.substr(4) "efg"
s.substr(0,3) "abc"
s.substr(2,4) "cdef"

// イテレータ要素のインデックス
distance(A.begin(), itr);
*/

int main()
{
    int n; cin >> n;
    vector<int> to[n];
    rep(_,n){
        int u; cin >> u; --u;
        int k; cin >> k;
        rep(i,k){
            int v; cin >> v; --v;
            to[u].push_back(v);
        }
    }

    int dist[n];
    rep(i,n) dist[i] = -1;

    queue<int> q;
    q.push(0);
    dist[0] = 0;

    while(!q.empty()){
        int u = q.front(); q.pop();
        for(int v: to[u]){
            if(dist[v] == -1){
                dist[v] = dist[u]+1;
                q.push(v);
            }
        }
    }
    rep(i,n){
        printf("%d %d\n", i+1, dist[i]);
    }
}