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

int md = 10000000;
vector <int> ro[101];
int s,d,v;
int s2,d2;
int kk[101],n;
bool flg[102] ;
int dmap[102][102];

void reset() {

  for(int i=0;i<=n;i++) {
    for(int j=0;j<=n;j++) {
	dmap[i][j] = 10000000;
    }
  }
}

void visit(int sn,int dis) {
  int x;

  //  for(int i=1;i<=n;i++)cout << flg[i];
  // cout <<" ";
  
  flg[sn+1] = 1;
  
  if(sn == d && dis <=100)  dmap[s][d] = min(dmap[s][d],dis);

  else if(dis <= 100 && dis < dmap[s][d]) {
    for(int i=0;i<ro[sn].size();i++) {
      
      if(flg[ro[sn][i]] == 0){
	//	cout <<sn+1 << "to"<<ro[sn][i] << endl;
	visit(ro[sn][i]-1,dis+1);
	flg[ro[sn][i]] = 0;
      }
    } 
  }
}
  
int main() {

  cin >> n;
  int a;
    
  for(int i=0;i<n;i++) {
    cin >> kk[i];
    cin >> a;
    ro[i].resize(a);
    for(int j=0;j<a;j++) cin >> ro[kk[i]-1][j];
  }

  reset();
  for(int k=0;k<=n;k++) flg[k] = 0;
  for(int i=0;i<n;i++) {
    for(int j=0;j<n;j++) {
      
      d = j;
      s = i;
      if(i != j) visit(i,1);
    }
  }
  
  int p;
  cin >> p;
  for(int i=0;i<p;i++) {
    cin >> s >> d >> v;

    if(dmap[s-1][d-1] <= v) 
      cout << dmap[s-1][d-1] << endl;
    else cout << "NA" << endl;
  
  }
  
  return 0;
  
}

C++: #include <iostream>
#include <queue>
#include <vector>
#include <set>
#include <algorithm>
#include <functional>
using namespace std;

const int INF = 1<<28;

struct edge_t {
    int from, to, cost;
    edge_t(int from, int to, int cost) : from(from), to(to), cost(cost) {}
    bool operator<(const edge_t &o) const {
        return (cost < o.cost);
    }
    bool operator>(const edge_t &o) const {
        return (cost > o.cost);
    }
};
struct state_t {
    int v;
    int min_cost;
    state_t(int v, int min_cost) : v(v), min_cost(min_cost) {}
    bool operator<(const state_t &o) const {
        return (min_cost < o.min_cost);
    }
    bool operator>(const state_t &o) const {
        return (min_cost > o.min_cost);
    }
};
typedef vector<edge_t> vertex_t;
struct graph_t {
    vector<vertex_t> g;

    graph_t() {}

    graph_t(int vertex_count) {
        g.resize(vertex_count);
    }
    graph_t(vector<vertex_t> g) : g(g) {}

    inline vertex_t& operator[](int index) {
        return g[index];
    }

    inline void push_back(vertex_t v) {
        g.push_back(v);
    }

    void dijkstra(int s, vector<int> &min_cost) {
        min_cost.resize(g.size());
        priority_queue< state_t, vector<state_t>, greater<state_t> > q;
        
        fill(min_cost.begin(), min_cost.end(), INF);

        min_cost[s] = 0;
        q.push(state_t(s, 0));

        while (!q.empty()) {
            state_t p = q.top(); q.pop();
            int v = p.v;
            if (min_cost[v] < p.min_cost) continue;
            for (int i = 0; i < g[v].size(); i++) {
                edge_t e = g[v][i];
                if (min_cost[e.to] > min_cost[v] + e.cost)  {
                    min_cost[e.to] = min_cost[v] + e.cost;
                    q.push(state_t(e.to, min_cost[e.to]));
                }
            }
        }
    }
};

int main() {
    int n; cin >> n;
    graph_t graph(n+1);
    for (int i = 1; i <= n; i++) {
        int r; cin >> r;
        int k; cin >> k;
        for (int j = 0; j < k; j++) {
            int t; cin >> t;
            graph[r].push_back(edge_t(r, t, 1));
        }
    }

    vector<int> min_cost;
    int p; cin >> p;
    for (int i = 0; i < p; i++) {
        int s, d, v;
        cin >> s >> d >> v;
        graph.dijkstra(s, min_cost);
        if (min_cost[d] < v) {
            cout << min_cost[d]+1 << endl;
        } else {
            cout << "NA" << endl;
        }
    }

    return 0;
}

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

using namespace std;

struct Packet{
	Packet(){
		ttl = current = 0;
	}

	void copy(Packet t){
		ttl = t.ttl;
		current = t.current;
		for(int i=0; i < 101; i++)checkTable[i] = t.checkTable[i];
	}

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

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

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

int main(){

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

	for(int i=1; i < 101; i++){
		for(int k=1; k < 101; k++){
			table[i][k] = 0;
			memo[i][k] = 0;
		}
	}

	scanf("%d",&n);

	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(t_limit <= 1){
			printf("NA\n");
			FLG = true;
		}

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

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

		while(!Q.empty()){
			tmp.copy(Q.front());
			Q.pop();

			if(tmp.ttl > 0 && 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 && t_limit-tmp.ttl + 1 <= n){
				for(int m=1; m <= n; m++){
					if(m != tmp.current && tmp.checkTable[m] == 0 && table[tmp.current][m] == 1){
						Packet q;
						q.copy(tmp);
						q.ttl--;
						q.set(m);
						Q.push(q);
					}
				}
			}
			if(FLG)break;
		}

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

	}

    return 0;
}