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 <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <cmath>
using namespace std;

#define MAX 1100
#define INF (1<<29)
#define EPS 1e-9

struct Point{
  int x, y, id;
};

vector<Point> bill;
double dist[MAX][MAX];
int prev[MAX];
int V;

void init(){
  bill.clear();
  for(int i = 0 ; i < MAX ; i++){
    for(int j = 0 ; j < MAX ; j++){
      dist[i][j] = INF;
      if(i == j) dist[i][j] = 0;
    }
  }
}

void dijkstra(int s){
  int d[MAX];
  bool used[MAX];
  fill(d, d+MAX, INF);
  fill(used, used+MAX, false);
  fill(prev, prev+MAX, -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] + dist[v][u]){
	d[u] = d[v] + dist[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;
}

inline double getDist(int from, int to){
  double ret = sqrt( ((bill[from].x - bill[to].x)*(bill[from].x - bill[to].x)) +
		     ((bill[from].y - bill[to].y)*(bill[from].y - bill[to].y)) );
  return ret;
}
  
int main(){
  while(cin >> V, V){
    init();
    Point p;
    for(int i = 0 ; i < V ; i++){
      cin >> p.id >> p.x >> p.y;
      p.id--;
      bill.push_back(p);
    }
    
    for(int i = 0 ; i < V ; i++){
      for(int j= 0 ; j < V ; j++){
	double dis = getDist(bill[i].id, bill[j].id);
	if(dis >= 50 + EPS) continue;
	dist[bill[i].id][bill[j].id] = dist[bill[j].id][bill[i].id] = dis;
      }
    }
    int m;    
    cin >> m;
    int s, g;
    while(m--){
      cin >> s >> g;
      s--, g--;
      dijkstra(s);
      vector<int> ans_path = get_path(g);
      if(ans_path.size() <= 1) cout << "NA" << endl;
      else{
	for(int i = 0 ; i < (int)ans_path.size() ; i++){
	  if(i == (int)ans_path.size()-1) cout << ans_path[i]+1 << endl;
	  else cout << ans_path[i]+1 << ' ';
	}
      }
    } 
  }
  return 0;
}

C++: #include<iostream>
#include<queue>
#include<algorithm>
#include<cmath>
#include<vector>

using namespace std;

typedef struct{
  int num;
  int x;
  int y;
}BILL;
typedef pair<int,int> P;
const int INF = (1<<20);
const int MAX = 1001;
BILL bill[MAX];
int pre[MAX],node[MAX];
int n,m;

void init(){
  fill(pre,pre+MAX, -1);
  fill(node,node+MAX, INF);
}


double Getd(BILL a, BILL b){
  return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));
}
void solve(int from, int to){

  init();
  node[from] = 0;
  priority_queue<P,vector<P>, greater<P> > Q;
  Q.push(P(node[from],from));
  //Q(distance,name)
  while(!Q.empty()){
    P now = Q.top(); Q.pop();
    for(int i = 1; i <= n; i++){
      int next = bill[i].num;
      if(Getd(bill[now.second],bill[i]) <= 50 && Getd(bill[now.second],bill[i]) > 0)
	if(node[next] > node[now.second]+Getd(bill[now.second],bill[i])){
	  //  cout << "come" << endl;
	  
	  //cout <<"able "   << now.second << " " << next << " " <<Getd(bill[now.second],bill[i]) << endl;
	  //cout << bill[now.second].x << " " << bill[now.second].y << endl;
	  node[next] = node[now.second]+Getd(bill[now.second],bill[i]);
	  Q.push(P(node[next],next));
	  pre[next] = now.second;
	}
    }
  }

  vector<int> V;
  int prec = to;
  if(node[to] == INF) cout << "NA";
  else {
    V.push_back(to);
    while(pre[prec] != -1){
      V.push_back(pre[prec]);
      prec = pre[prec];
    }
  }
  reverse(V.begin(),V.end());
  for(int i = 0; i < V.size(); i++){
    if(i) cout << " ";
    cout << V[i];
  }
  cout << endl;
}

int main(){
  while(cin >> n && n){
    for(int i = 1; i <= n; i++)
      cin >> bill[i].num >> bill[i].x >> bill[i].y;
    
    cin >> m;
    for(int i = 0; i < m; i++){
      int f,t;
      cin >> f >> t;
      solve(f,t);
    }
  }
  return 0;
}