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++: //Breadth First Search
#include <iostream>
#include <queue>

using namespace std;

static const int N = 100;

int n, M[N][N];
int d[N];
queue<int> Q;

void bfs() {
    int u;
    for(int i = 0; i < N; i++) d[i] = -1;
    Q.push(0);
    d[0] = 0;
    while(!Q.empty()) {
        u = Q.front();
        for(int i = 0; i < n; i++) {
            if(M[u][i] == 1 && d[i] == -1) {
                Q.push(i);
                d[i] = d[u] + 1;
            }
        }
        Q.pop();
    }
    for(int i = 0; i < n; i++) {
        cout << i + 1 << " " << d[i] << endl;
    }
}

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

    bfs();
}

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

int n,m[101][101];
int d[101],t=0,vis[101];
queue<int> q;

void bfs(){
    q.push(1);
    d[1] = 1;
    int u,v;
    while( !q.empty() ){
        u = q.front();
        q.pop();
        for( v = 1; v <= n; v++ ){
            if( m[u][v]==0 || d[v]) continue;
            d[v] = d[u]+1;
            q.push(v);
        }
    }
    for( int i = 1; i <= n; i++ ){
        cout << i << " " << (d[i]-1) << endl;
    }
}

int main(){
    int i,j,k,u,v,du;
    scanf("%d",&n);
    k = n;
    while(k--){
        scanf("%d",&u);
        scanf("%d",&du);
        while(du--){
            scanf("%d",&v);
            m[u][v]  = 1;
        }
    }
    bfs();
}

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

int G[110][110] = {0}; /*G????????????????????????????????????????????????, ??????1?????¨??????????????????*/

int n;
int D[110]; /*D???????????????????¨?????????°????????????????????????????????????*/
void bfs(int src){
  
  // cerr << "bfs root = " << src << endl;
  queue<int> Q;
  Q.push(src);
  D[src] = 0;
  while(! Q.empty()) {
    int cur = Q.front();
    Q.pop();
    // cerr << "visiting " << cur << ' ' << D[cur] << endl;
    for(int i=1; i<=n; i++){
      if(G[cur][i]==1 && D[i]==0){
	D[i] = D[cur]+1;
	Q.push(i);
      }
    }
  }

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

int main(){

  cin >> n;
  int u, k;
  int v[100000];
  for(int i=0; i<n; i++){
    cin >> u >> k;
    for(int j=0; j<k; j++){
      cin >> v[j];
      G[i+1][v[j]] = 1;
    }
  }

  bfs(1);
}

C++: #include<algorithm>
#include<bitset>
#include<iostream>
#include<iomanip>
#include<set>
#include<string>
#include<math.h>
#include<string>
#include<queue>
#include<vector>
using namespace std;
typedef long long int ll;
typedef pair<int, ll> P;

class zahyo{
	public:
	int x;
	int y;
	zahyo(){
		x=0;
		y=0;
	}
	zahyo(int x_,int y_){
		x=x_;
		y=y_;
	}
	void print(){
		cout<<x<<" "<<y;
	}
	zahyo operator+(zahyo add){
		add.x=this->x+add.x;
		add.y=this->y+add.y;
		return add;
	}
	zahyo operator-(zahyo add){
		add.x=this->x-add.x;
		add.y=this->y-add.y;
		return add;
	}
	bool operator==(const zahyo add) const{
		if(add.x==this->x and add.y==this->y){return true;}
		else{return false;}
	}
	bool operator!=(const zahyo add) const{
		if(add.x==this->x or add.y==this->y){return false;}
		else{return true;}
	}
	bool operator<(const zahyo add) const{
		if(this->x<add.x){return true;}
		else if(this->x==add.x and this->y<add.y){return true;}
		else{return false;}
	}
	bool operator>(const zahyo add) const{
		if(this->x>add.x){return true;}
		else if(this->x==add.x and this->y>add.y){return true;}
		else{return false;}
	}
	void input(){
		cin>>x>>y;
	}
};


int main(){
	int glaph[100][100]={};
	int n;
	cin>>n;
	for(int i=0;i<n;i++){
		int k;
		cin>>k>>k;
		for(int j=0;j<k;j++){
			int v;
			cin>>v;
			v--;
			glaph[i][v]=1;
		}
	}
	queue<int> widesearch;
	int ans[100]={};
	int counter=1;
	ans[0]=1;
	widesearch.push(0);
	while(widesearch.size()>0){
		counter++;
		int size=widesearch.size();
		for(int i=0;i<size;i++){
			int from=widesearch.front();
			widesearch.pop();
			for(int j=0;j<n;j++){
				if(glaph[from][j]==1 and ans[j]==0){
					ans[j]=counter;
					widesearch.push(j);
				}
			}
		}
	}
	for(int i=0;i<n;i++){
		cout<<i+1<<" "<<ans[i]-1<<endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
const int N = 101;
const int CRL = -1;
int adj[N][N] = {0};
int d[N]={0};
int kai[N];

int main()
{
    int n;
    memset(d, CRL, sizeof(d));
    d[1]=0;
    queue <int> q;
    q.push(1);
    cin >> n;
    for(int i=1;i<=n;i++){
    	int k;
    	int l;
    	cin >> l >> k;
    	kai[i]=l;
    	for(int j=1;j<k+1;j++){
    		int m;
    		cin >> m;
    		adj[i][j] = m;
    	}
    }
    while(q.size()){
    	int k = q.front();
    	q.pop();
    	for(int i=1;i<kai[i]+1;i++){
    		if(d[adj[k][i]]==CRL){
    			d[adj[k][i]] = d[k]+1;
    			q.push(adj[k][i]);
    		}
    	}
    }
    for(int i=2;i<N;i++)
    	if(d[i]==0)d[i]=-1;
    for(int i=1;i<=n;i++){
    	cout << i << " " << 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 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] == 0)
            continue;
            if(d[v] != INFTY)
            continue;
            d[v] = d[u] + 1;
            q.push(v);
        }
    }
    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;
    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<queue>
#include<math.h>
#include<cmath>
#include<bitset>
#include<stdio.h>
#include<string>
#include<map>
#include<algorithm>
#include<vector>
#include<iostream>
#include<utility>
using namespace std;
int main(){
  vector<vector<int> > g(110);
  int INF=(1<<29);
  int x,n,i,j,v,k,u,ans[110];
  queue<int> q;
  scanf("%d\n",&n);
  for(i=0;i<n;i++){
    scanf("%d %d",&u,&k);
    u--;
    for(j=0;j<k;j++){
      scanf("%d",&v);
      v--;
      g[u].push_back(v);
    }
  }
  for(i=0;i<n;i++){
    ans[i]=INF;
  }
  q.push(0);
  ans[0]=0;
  while(!q.empty()){
    x=q.front();
    q.pop();
    for(i=0;i<g[x].size();i++){
      if(ans[g[x][i]]>ans[x]+1){
        ans[g[x][i]]=ans[x]+1;
        q.push(g[x][i]);
      }
    }
  }
  for(i=0;i<n;i++){
    if(ans[i]==INF){
      ans[i]=-1;
    }
  }
  for(i=0;i<n;i++){
    printf("%d %d\n",i+1,ans[i]);
  }
  return 0;
}