Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	dd := make([][]int, 1000)
	for i := range dd {
		dd[i] = make([]int, 1000)
	}
	num := make([]int,1000)
	inv := make([]int, 1001)
	x := make([]int, 1000)
	y := make([]int, 1000)
	vv := make([]int, 1000)
	nowt := make([]float64, 1000)
	rev := make([]int, 1000)
	for scanner.Scan() {
		n, _ := strconv.Atoi(scanner.Text())
		if n == 0 {
			break
		}
		for i := 0; i < n; i++ {
			scanner.Scan()
			buf1 := strings.Split(scanner.Text(), " ")
			num[i], _ = strconv.Atoi(buf1[0])
			x[i], _ = strconv.Atoi(buf1[1])
			y[i], _ = strconv.Atoi(buf1[2])
			inv[num[i]] = i
		}
		for i := 0; i < n; i++ {
			for j := 0; j < n; j++ {
				dd[i][j]=(x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j])
			}
		}
		scanner.Scan()
		m, _ := strconv.Atoi(scanner.Text())
		for i := 0; i < m; i++ {
			scanner.Scan()
			buf2 := strings.Split(scanner.Text(), " ")
			c, _ := strconv.Atoi(buf2[0])
			d, _ := strconv.Atoi(buf2[1])
			c = inv[c]
			d = inv[d]
			for j := 0; j < n; j++ {
				vv[j] = 0
				nowt[j]=999999999
				rev[j]=-1
			}
			nowt[c]=0
			for j := 0; j < n; j++ {
				M := 99999999
				at := 0
				for k := 0; k < n; k++ {
					if vv[k] == 0 && float64(M) > nowt[k] {
						M=int(nowt[k])
						at = k
					}
				}
				if M > 90000000 {
					break
				}
				vv[at]=1
				for k := 0; k < n; k++ {
					if vv[k] == 0 && dd[at][k]<=2500&&nowt[k]>nowt[at]+math.Sqrt(float64(dd[at][k])) {
						nowt[k]=nowt[at]+math.Sqrt(float64(dd[at][k]))
						rev[k] = at
					}
				}
			}
			if vv[d] == 0 {
				fmt.Println("NA")
			} else {
				stack := make([]int, 0)
				V := d
				for V != c {
					stack = append(stack, V)
					V = rev[V]
				}
				fmt.Print(num[c])
				for len(stack) > 0 {
					fmt.Printf(" %d", num[stack[len(stack)-1]])
					stack = stack[:len(stack)-1]
				}
				fmt.Println()
			}
		}
	}
}

C++: #include <set>
#include <map>
#include <list>
#include <queue>
#include <stack>
#include <cmath>
#include <ctype.h>
#include <ctime>
#include <cstdio>
#include <vector>
#include <string>
#include <bitset>
#include <cctype>
#include <cstdlib>
#include <cstring>
#include <utility>
#include <numeric>
#include <complex>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <iostream>
#include <iterator>
#include <algorithm>

using namespace std;

#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i, n) REP(i, 0, n)
#define lengthof(x) (sizeof(x) / sizeof(*(x)))
#define FILL(ptr, value) FILL_((ptr), sizeof(ptr)/sizeof(value), (value))
template <typename T>
void FILL_(void * ptr, size_t size, T value){
  std::fill((T*)ptr, (T*)ptr+size, value);
}
//4方向ベクトル→↑←↓
int dx[] ={1,0,-1,0};
int dy[] ={0,-1,0,1};
int n;//ビルの数
int m;//移動情報の個数
const int INF = 1e+9;
typedef pair<int,int> P;
double d[1001];//2点間の最短距離
int prev[1001];//直前の頂点
bool used[1001];
double cost[1001][1001];

void dijkstra(int s){
  fill(d,d+1000,INF);
  fill(used,used+1000,false);
  d[s] = 0;
  while(1){
    int v = -1;
    //まだ使われていない頂点のうち距離が最小のものを探す
    for(int u = 0;u <n;u++){
      if(!used[u]&&(v==-1||d[u]<d[v]))
	v = u;
    }
    if(v==-1)
      break;
    used[v] =true;
    for(int u = 0;u <n;u++){
      if(d[u]>d[v]+cost[v][u]){
	d[u] =d[v]+cost[v][u];
	prev[u] = v;
      }
    }
  }
}
int main()
{
  while(cin>>n,n){
    for(int i = 0;i <=1000;i++){
      for(int j = 0;j <=1000;j++){
	cost[i][j] = INF;
      }
    }
    map<int,P> build;
    build.clear();
    int b,x,y;
    for(int i = 0;i <n;i++){
      cin>>b>>x>>y;
      b--;
      build[b]=P(x,y);
    }
    for(int i = 0;i <=1000;i++){
      for(int j = 0;j <=1000;j++){
	if(i!=j)
	  cost[i][j] =INF;
	else
	  cost[i][j] = 0;
      }
    }
    
    for(int i = 0;i <n;i++){//距離が50以下の距離なら道があるとする。
      for(int j = 0;j <n;j++){
	int d =(build[i].first-build[j].first)*(build[i].first-build[j].first)+(build[i].second-build[j].second)*(build[i].second-build[j].second);
	if(d<=2500){
	  cost[i][j] = sqrt(d);
	  cost[j][i] = sqrt(d);
	}
      }
    }
    
    cin>>m;
    int s,g;//スタートとゴール
    stack<int> path;
    for(int i = 0;i <m;i++){
      cin>>s>>g;
      s--;
      g--;
      dijkstra(s);
      if(d[g]!=INF){
	for(int j =g;j !=s;j =prev[j]){
	  path.push(j);
	}
	path.push(s);
	int k=	path.size();
	for(int j = 0;j <k;j++){
	  cout <<path.top()+1;
	  path.pop();
	  if(j==k-1)
	    cout <<endl;
	  else
	    cout <<" ";
	}
      }
      else{
	cout <<"NA"<<endl;
      }
    }
  }
  return 0;
}

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

using namespace std;

typedef vector<int> vi;
typedef vector<vi> vii;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef vector<vb> vbb;
typedef pair<int, int> pii;
typedef long long ll;
typedef unsigned long long ull;

#define all(a)  (a).begin(),(a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair

#define loop(i,a,b) for(int i=(a);i<ull(b);++i)
#define rep(i,n) loop(i,0,n)

#define MAX 1010

const double eps = 1e-10;
const double pi  = acos(-1.0);
const double inf = (int)1e8;

int n;
double cost[MAX][MAX];
int num[MAX];
vector<pair<int, int> > v;

int prev[MAX];
double d[MAX];
bool used[MAX];
int V;

void dijkstra(int s){
    fill(d, d+V, inf);
    fill(used, used+V, false);
    fill(prev, prev+V, -1);
    d[s] = 0;

    while(true){
        int v = -1;
        for(int u=0; u < V; u++){
            if(!used[u] && (v==-1 || d[u] < d[v])) v = u;
        }

        if(v == -1)break;
        used[v] = true;

        for(int u=0; u < V; u++){
            if(d[u] > d[v] + cost[v][u]){
                d[u] = d[v] + cost[v][u];
                prev[u] = v;
            }
        }
    }
}

vector<int> get_path(int t){
    vector<int> path;
    for(; t != -1; t = prev[t]) path.push_back(t);
    reverse(path.begin(), path.end());
    return path;
}

int main(){
    while(cin >> n, n){
        V = n;
        v.clear();
        rep(i, n){
            int b, x, y;
            cin >> b >> x >> y;
            num[i] = b; v.push_back(make_pair(x, y));
        }
        rep(i, n)rep(j, n){
            if(i == j) {cost[i][j] = inf; continue;}
            double d = abs(sqrt(pow(v[i].first-v[j].first, 2)+pow(v[i].second-v[j].second, 2)));
            if(d-50.0 <= eps){/*cout << i << " " << j << " " << d << endl;*/ cost[i][j] = d;}
            else cost[i][j] = inf;
        }
        int m;
        cin >> m;
        rep(i, m){
            int s, g;
            cin >> s >> g; s--; g--;
            dijkstra(s);
            vector<int> p = get_path(g);

            if(p.size() == 1) cout << "NA" << endl;
            else {
                rep(j, p.size()) cout << (j==0?"":" ") << num[p[j]];
                cout << endl;
            }
        }
    }
}