Go: package main

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

type Queue []int

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

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

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

	nVerts := scanInt(sc)
	graph := make([][]int, nVerts+1)

	for i := 0; i < nVerts; i++ {
		u := scanInt(sc)
		nDegrees := scanInt(sc)

		graph[u] = make([]int, nDegrees)
		for d := 0; d < nDegrees; d++ {
			graph[u][d] = scanInt(sc)
		}
	}

	paths := make([]int, nVerts+1)

	queue := Queue(make([]int, 0))
	queue.push(1)
	paths[1] = 1

	for len(queue) > 0 {
		u := queue.pop()
		d := paths[u] + 1
		for _, v := range graph[u] {
			if paths[v] == 0 {
				paths[v] = d
				queue.push(v)
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 1; i <= nVerts; i++ {
		fmt.Fprintf(w, "%d %d\n", i, paths[i]-1)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

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

int dt[101][101];
int d[101];

int n;
int t=0;
void bfs(int s){
	priority_queue<int, vector<int>, greater<int> > que;
	for(int i=1;i<=n;i++)
		d[i]=-1;
	d[s]=0;
	que.push(s);
	while(!que.empty()){
		int nxt=que.top();que.pop();
		for(int i=1;i<=n;i++){
			if(dt[nxt][i]&&d[i]==-1){
				que.push(i);
				d[i]=d[nxt]+1;
			}
		}
	}
}
int main(){
	int fi, v, g;
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		scanf("%d %d",&fi,&v);
		for(int j=1;j<=v;j++){
			scanf("%d",&g);
			dt[fi][g]=1;
		}
	}
	d[1]=0;
	bfs(1);
	for(int i=1;i<=n;i++){
		if(!d[i]){
			bfs(i);
		}
	}
			
	for(int i=1;i<=n;i++){
		printf("%d %d\n",i,d[i]);
	}
	return 0;
}

C++: #include <cstdio>
#include <queue>
using namespace std;
#define MAX_N 100

int g[MAX_N+1][MAX_N+1];
int d[MAX_N+1];
bool visited[MAX_N+1];
queue<int> que;

int n;
int t = 1;

void bfs(int id) {
  visited[id]=true;
  que.push(id);
  queue<int> next_que;
  while(!que.empty()) {
    int v = que.front(); que.pop();
    for(int u=1;u<=n;u++) {
      if(g[v][u]!=0 && !visited[u]) {
        visited[u]=true;
        next_que.push(u);
        d[u] = t;
      }
    }
    if(que.empty()){
      que = next_que;
      while(!next_que.empty()) next_que.pop();
      t++;
    }
  }
}

int main() {
  scanf("%d\n",&n);
  int u,k,v;
  for(int i=0;i<n;i++) {
    scanf("%d %d ",&u,&k);
    for(int j=0;j<k;j++) {
      scanf("%d ",&v);
      g[u][v] = 1;
    }
  }
  bfs(1);
  for(int i=1;i<=n;i++) {
    if(visited[i])
      printf("%d %d\n",i,d[i]);
    else
      printf("%d -1\n",i);
  }
}

C++: #include<iostream>
#include<queue>
using namespace std;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;
static const int N = 100;
static const int INFTY = (1 << 21);

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

void bfs(int s){
    for(int i = 0; i < n; i++){
        color[i] = WHITE;
        d[i] = INFTY;
    }

    queue<int> q;
    color[s] = GRAY;
    d[s] = 0;
    q.push(s);

    while(!q.empty()){
        int u = q.front(); q.pop();
        for(int v = 0; v < n; v++){
            if(M[u][v] && color[v] == WHITE){
                color[v] = GRAY;
                d[v] = d[u] + 1;
                q.push(v);
            }
        }
        color[u] = BLACK;
    }

    for(int i = 0; i < n; i++){
        if(d[i] != INFTY) cout << i + 1 << " " << d[i] << endl;
        else cout << i + 1 << " " << -1 << endl;
    }
}

int main(){
    cin >> n;
    int u, k, v;
    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;
        for(int j = 0; j < k; j++){
            cin >> v;
            M[u-1][v-1] = 1;
        }
    }
    bfs(0);

    return 0;
}

C++: // 2015/01/05 Tazoe

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

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

	int G[100][100] = {0};

	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-1][v-1] = 1;
		}
	}

	int d[100];
	for(int i=0; i<n; i++){
		d[i] = -1;
	}

	queue<int> Q;

	Q.push(0);
	d[0] = 0;

	while(!Q.empty()){
		int u = Q.front();

		int v = -1;
		for(int j=0; j<n; j++){
			if(G[u][j]==1 && d[j]==-1){
				v = j;
				break;
			}
		}

		if(v!=-1){
			Q.push(v);
			d[v] = d[u]+1;
		}
		else{
			Q.pop();
		}
	}

	for(int i=0; i<n; i++){
		cout << i+1 << ' ' << d[i] << endl;
	}

	return 0;
}

C++: #include <iostream>
#include <queue>
using namespace std;
static const int N=100;
static const int INFTY=(1<<21);

int n,M[N][N];
int d[N];
void kansuu(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 i=0;i<n;i++){
      if(M[u][i]==0) continue;
      if(d[i]!=INFTY) continue;
      d[i]=d[u]+1;
      q.push(i);
    }
  }
  for(int i=0;i<n;i++){
    if(d[i]==INFTY) d[i]=-1;
    cout<<i+1<<" "<<d[i];
    printf("\n");
  }
}
int main(void){
  int u,k,v;
  cin>>n;
  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;
    }
  }
  kansuu(0);
  return 0;
}

C++: // http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_A
// Graph I - Breadth First Search

#define SUBMIT

#include <utility>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <vector>
#include <stack>
#include <limits>
#include <numeric>
#include <functional>
#include <set>
#include <cmath>
#include <cstring>
#include <climits>
#include <memory>
#include <queue>

using namespace std;
using ui64 = unsigned long long;
using i64 = long long;

const ui64 MAX_N = 100;

enum class color_type {
    white,
    gray
};

const int NIL = -1;

int adj[MAX_N][MAX_N];
color_type color[MAX_N];
int dist[MAX_N];
int n;
queue<int> q;

void bfs(int u) {
    q.push(u);

    while (!q.empty()) {
        u = q.front();
        q.pop();

        for (int v = 0; v < n; ++v) {
            if (adj[u][v] == 1 && color[v] == color_type::white) {
                q.push(v);
                color[v] = color_type::gray;
                dist[v] = dist[u] + 1;
            }
        }
    }
}

void start_bfs() {
    while (!q.empty()) q.pop();

    dist[0] = 0;
    color[0] = color_type::gray;
    bfs(0);
}

int main() {
    memset(adj, 0, sizeof(adj));
    memset(dist, NIL, sizeof(dist));
    cin >> n;

    int u, degree;
    for (int i = 0; i < n; ++i) {
        cin >> u >> degree;
        u--; // 0-origin

        int v;
        for (int j = 0; j < degree; ++j) {
            cin >> v;
            v--; //0-origin
            adj[u][v] = 1;
        }
    }

    start_bfs();
    for (int v = 0; v < n; ++v) cout << v + 1 << " " << dist[v] << endl;
    return 0;
}