Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)

	g := make([][]int, n+1)
	d := make([]int, n+1)
	for i := 0; i < n; i++ {
		var u,k int
		fmt.Scan(&u)
		fmt.Scan(&k)
		g[u] = make([]int, k)
		for j := 0; j < k; j++ {
			fmt.Scan(&g[u][j])
		}

		d[i+1] = -1
	}

	q := [][]int{}
	q = append(q, []int{1, 0})
	for len(q) > 0 {
		pop := q[0]
		if len(q) > 1 {
			q = q[1:]
		} else {
			q = [][]int{}
		}
		if d[pop[0]] >= 0 {
			continue
		}
		d[pop[0]] = pop[1]

		for j := 0; j < len(g[pop[0]]); j++ {
			q = append(q, []int{g[pop[0]][j], pop[1]+1})
		}
	}

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

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;
}

C++: #include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<vector>
#include<queue>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
using namespace std;

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef stack<int> SI;
typedef queue<int> QI;
typedef pair<int,int> PII;
typedef long long LL;

#define d(x)  cout<<#x<<" = "<<(x)<<endl;
#define c cout<<"#"<<endl;
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define REACH(i,c) for(typeof((c).rbegin()) i=(c).rbegin(); i!=(c).rend(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c,n) sort(c,c+n)
#define VSORT(c) sort((c).begin(),(c).end())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define DFOR(i,b,a) for(int i=(b)-1;i>=(a);--i)
#define DREP(i,n) DFOR(i,n,0)
#define INF 2000000000

const double EPS = 1e-10;
const double PI  = acos(-1.0);
////////////////////////////////////////////////
int n,a[101][101],d[101],p[101];
QI q;
int main()
{
	cin>>n;
	FOR(i,1,n+1)
	{
		int k,m;cin>>k>>m;
		a[k][0]=m;
		FOR(j,1,m+1)
		{	
			int x;cin>>x;
			a[k][j]=x;
		}
	}
	REP(i,101)p[i]=1;
	for(q.push(1);SZ(q)!=0;)
	{
		int u=q.front();
		q.pop();
		for(;p[u]<=a[u][0];)
		{
			int v=a[u][p[u]];p[u]++;
			if(v!=1&&d[v]==0)
			{
				d[v]=d[u]+1;
				q.push(v);
			}
		}
	}
	FOR(i,1,n+1)
	{
		cout<<i<<" "<<d[i]<<endl;
	}
	return 0;
}

C++: #include <queue>
#include <map>
#include <cstdio>

using namespace std;

int main(){
	int t=0,T,i,j,k;
	map<int,vector<int> >a;
	for(scanf("%d",&T); t<T; t++)for(scanf("%d%d",&i,&k); k--; a[i].push_back(j))scanf("%d",&j);
	map<int,int>m;
	queue<int>q;
	for(q.push(1),m[1]=1;!q.empty();){
		k = q.front();
		q.pop();
		for (i = 0; i < a[k].size(); i++){
		    if(!m[a[k][i]])m[a[k][i]]=m[k]+1,q.push(a[k][i]);
		}
	}
	for(i=1;i<=T;i++){
	    printf("%d %d\n",i,m[i]-1);
	}
}