Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)
const INF = 1<<31

func main() {
	scanner.Scan()
	n, _ := strconv.Atoi(scanner.Text())
	arr := make([][]int, n)
	for i := range arr {
		arr[i] = make([]int, n)
	}
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			arr[i][j] = INF
		}
	}
	for i := 0; i < n; i++ {
		scanner.Scan()
		buf := strings.Split(scanner.Text(), " ")
		input := make([]int, len(buf))
		for j := range input {
			input[j], _ = strconv.Atoi(buf[j])
		}
		x, k := input[0]-1, input[1]
		for j := 0; j < k; j++ {
			y := input[j+2]-1
			arr[x][y] = 1
		}
	}
	for k := 0; k < n; k++ {
		arr[k][k] = 0
		for i := 0; i < n; i++ {
			if arr[i][k] >= INF {
				continue
			}
			for j := 0; j < n; j++ {
				if arr[k][j] >= INF {
					continue
				}
				arr[i][j] = min(arr[i][j], arr[i][k]+arr[k][j])
			}
		}
	}
	scanner.Scan()
	p, _ := strconv.Atoi(scanner.Text())
	for i := 0; i < p; i++ {
		scanner.Scan()
		buf := strings.Split(scanner.Text(), " ")
		input := make([]int, len(buf))
		for j := range input {
			input[j], _ = strconv.Atoi(buf[j])
		}
		s, d, v := input[0]-1, input[1]-1, input[2]
		if arr[s][d] < v {
			fmt.Println(arr[s][d]+1)
		} else {
			fmt.Println("NA")
		}
	}
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

C++: #include <bits/stdc++.h>

using namespace std;

// 1 to 0-indexed
vector<int> G[100];

typedef pair<int, int> Pii;
typedef pair<int, Pii> Piii;

int bfs(int S, int T, int TTL) {
  
  int memo[100];
  memset(memo, -1, sizeof(memo));
  memo[S] = 0;
  queue<Piii> Q;
  Q.push(Piii(0, Pii(S, TTL)));
  while(!Q.empty()) {
    
    Piii piii = Q.front(); Q.pop();
    
    int cost = piii.first;
    int now = piii.second.first;
    int ttl = piii.second.second;
    
    if(now == T) return cost;
    if(memo[now] < cost) continue;

    if(ttl <= 1) continue;
    
    for(int i=0; i<G[now].size(); i++) {
      int to = G[now][i];
      if(memo[to] == -1) {
	memo[to] = cost + 1;
	Q.push(Piii(cost+1, Pii(to, ttl-1)));
      }
    }
  }
  
  return -1;
}

int main() {
  
  int N;
  while(cin >> N) {
    
    for(int i=0; i<100; i++) G[i].clear();
    
    for(int i=0; i<N; i++) {
      int r; cin >> r; r--;
      int k; cin >> k;
      for(int i=0; i<k; i++) {
	int x; cin >> x; x--;
	G[r].push_back(x);
      }
    }
    
    int Q; cin >> Q;
    while(Q--) {
      int s, t, v;
      cin >> s >> t >> v; s--, t--;
      int res = bfs(s, t, v);
      if(res >= 0) {
	cout << res+1 << endl;
      }
      else {
	cout << "NA" << endl;
      }
    }
    
  }
  
  return 0;
}

C++: #include <stdio.h>
#include <cmath>
#include <algorithm>
#include <queue>

using namespace std;

struct Packet{
	Packet(){}

	Packet(int arg_ttl,int loc){
		ttl = arg_ttl;
		went_num = 1;
		for(int i=0; i < 101; i++)checkTable[i] = 0;
		checkTable[loc] = 1;
		current = loc;
	}

	void set(int loc){
		checkTable[loc] = 1;
		current = loc;
		went_num++;
	}

	int ttl,checkTable[101],went_num,current;
};

int main(){

	int n,r,k,to,table[101][101],num_of_packet,start,goal,t_limit,memo[101][101];
	Packet tmp;

	while(scanf("%d",&n)!=EOF){
		for(int i=1; i <= n; i++){
			for(int k=1; k <= n; k++){
				table[i][k] = 0;
				memo[i][k] = 0;
			}
		}

		for(int i = 0; i < n; i++){
			scanf("%d %d",&r,&k);
			for(int p=0;p < k; p++){
				scanf("%d",&to);
				table[r][to] = 1;
			}
		}

		scanf("%d",&num_of_packet);

		queue<Packet> Q;
		bool FLG;

		for(int i=0; i < num_of_packet; i++){
			scanf("%d %d %d",&start,&goal,&t_limit);

			FLG = false;

			if(memo[start][goal] != 0){
				if(memo[start][goal] <= t_limit){
					printf("%d\n",memo[start][goal]);
				}else{
					printf("NA\n");
				}
				continue;
			}

			for(int i = 1; i <= n; i++){
				if(i != start && table[start][i] == 1){
					if(memo[i][goal] > 0 && memo[i][goal] < t_limit){
						printf("%d\n",memo[i][goal]+1);
						memo[start][goal] = memo[i][goal]+1;
						FLG = true;
						break;
					}
					Packet p(t_limit-1,start);
					p.set(i);
					Q.push(p);
				}
			}



			while(!Q.empty() && FLG == false){
				tmp = Q.front();
				Q.pop();

				if(tmp.current == goal){
					printf("%d\n",t_limit - tmp.ttl+1);
					FLG = true;

					while(!Q.empty())Q.pop();

					memo[start][goal] = t_limit - tmp.ttl+1;

					break;
				}

				if(tmp.ttl > 1 && tmp.went_num < n){
					for(int i=1; i <= n; i++){
						if(i != tmp.current && tmp.checkTable[i] == 0 && table[tmp.current][i] == 1){
							if(memo[i][goal] > 0 && memo[i][goal] < tmp.ttl){
								printf("%d\n",t_limit-tmp.ttl+memo[i][goal]+1);
								memo[start][goal] = t_limit-tmp.ttl+memo[i][goal]+1;
								FLG = true;
								while(!Q.empty())Q.pop();
								break;
							}

							Packet p = tmp;
							p.ttl--;
							p.set(i);
							Q.push(p);
						}
					}
				}
			}

			if(!FLG){
				printf("NA\n");
			}
		}
	}

    return 0;
}

C++: #include <iostream>
#include <queue>

using namespace std;


static const int NO = -2;
static const int N = 300;


int graph[N + 1][N + 1] = {{}};
int dis[N + 1] = {};
int n;

void bfs(int v){
  queue<int> Q;

  Q.push(v);

  for(int i = 1; i <= N; i++){
    dis[i] = NO;
  }

  dis[v] = 1;

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

    for(int i = 1;i <= n; i++){
      if(graph[u][i]==0) continue;
      if(dis[i]!=NO)continue;
      dis[i] = dis[u] + 1;
      Q.push(i);

    }
  }
}

int main(){

  int r[N+1] = {};
  int d[N+1] = {};
  int k[N+1] = {};
  int f[N+1] = {};
  int p,s[N+1] = {};
  int v[N+1] = {};


  //in
  cin >> n;

  for(int i = 1;i <= n; i++){

    cin >> r[i] >> k[i];

    for(int j = 1;j <= k[i];j++){

      cin >> f[j];
      graph[r[i]][f[j]] = 1;
    }
  }

  cin >> p;
  for(int i = 1;i <= p; i++){
    cin >> s[i] >> d[i] >> v[i];
    bfs(s[i]);

    if(v[i] >= dis[d[i]]) cout << dis[d[i]] << endl;
    else cout << "NA" << endl;
  }
}