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){
  double 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;
}

double getDist(int from, int to){
  double ret = sqrt( 1.0 * ( ((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= i+1 ; j < V ; j++){
	double dis = getDist(bill[i].id, bill[j].id);
	//if(dis >= 50 + EPS) continue;
	if(dis <= 50 + EPS){
	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 <cstdio>
#include <cstring>
#include <iostream>
#include <queue>
using namespace std;

const int INF=10000;

typedef struct{
	int num;
	int x;
	int y;
}building;

bool canMove(building p, building q){
	bool ret=false;
	int dx=p.x-q.x;
	int dy=p.y-q.y;
	
	//?????¢???50??\??????????§???????
	if(dx*dx+dy*dy <= 50*50) ret=true;
	
	return ret;
}

int main(){
	while(1){
		int n;
		int b[1001][1001];
		building a[1000];
						
		scanf(" %d", &n);
		if(n==0) break;
		for(int i=0; i<n; ++i)
			scanf(" %d %d %d", &a[i].num, &a[i].x, &a[i].y);
		
		//?????????
		for(int i=0; i<=1000; ++i)
		for(int j=0; j<=1000; ++j)
		b[i][j]=INF;
		
		//??\?¶???????????????????????????????1	
		for(int i=0; i<n; ++i){
			b[a[i].num][a[i].num]=1;
			for(int j=i+1; j<n; ++j){
				if(canMove(a[i], a[j])){
					b[a[i].num][a[j].num]=1;	
					b[a[j].num][a[i].num]=1;	
				}
			}
		}
		
		//?????¨????????????
		int m;
		scanf(" %d", &m);
		for(int i=0; i<m; ++i){
			int s, g;
			scanf(" %d %d", &s, &g);
			
			//?????????????????????
			int d[1001];
			int prev[1001];
			
			for(int j=0; j<=1000; ++j) d[j]=INF;
			d[s]=0;
			memset(prev, -1, sizeof(prev));
			
			queue<int> que;
			bool remain[1001]; //??¢?´¢????±?????????£????????????
			for(int j=0; j<=1000; ++j) remain[j]=false;
			
			for(int j=0; j<n; ++j){
				que.push(a[j].num);
				remain[a[j].num]=true;
			}
			
			int ct=0;
			while(ct<n){
				int pp=-1;
				int min=INF;
				
				for(int j=0; j<n; ++j){	
					int nj=a[j].num;
					if(remain[nj]){
						if(min>d[nj]){
							pp=nj;	
							min=d[nj];
						}
					}	
				}
				
				int u=pp;
				remain[u]=false;
				
				for(int j=0; j<n; ++j){
					int nj=a[j].num;
					if(b[u][nj]==1){
						if(d[nj]>d[u]+1){
							d[nj]=d[u]+1;
							prev[nj]=u;	
						}	
					}
				}
				//printf(" pp=%d\n", pp);
				ct++;
			}
			
			if(d[g]==INF) printf("NA\n");
			else{
				int now=1;
				int ans[1000];
				ans[0]=g;
				
				int bb=g;
				while(prev[bb] != s){
					ans[now++]=prev[bb];	
					bb=prev[bb];
				}
				ans[now]=s;
				
				for(int i=now; i>=0; --i){
					if(i!=now) printf(" ");	
					printf("%d", ans[i]);
				}
				printf("\n");
			}
			
		}
		
	}
}