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 <iomanip>
#include <string>
#include <sstream>
#include <algorithm>
#include <vector>
#include <utility>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <functional>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
 
using namespace std;
 
#define REP(i,s,e) for(int i=(s); i<(int)(e); i++)
#define rep(i,n) REP(i, 0, n)
#define pb push_back
#define mp make_pair
#define all(r) (r).begin(),(r).end()
#define rall(r) (r).rbegin(),(r).rend()
#define fi first
#define se second
 
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef vector<ll> vl;
typedef vector<vl> vll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
 

 
const int INF = 1000000;
const double EPS = 1e-8;
const int mod = 1e9 + 7;
//const double D_INF = 1e18;

const double PI = acos(-1);

int dx[] ={-1,0,1,0};
int dy[] ={0,-1,0,1};

struct Edge
{
	int t, c;
	Edge(){};
	Edge(int t, int c) : t(t), c(c){};
};

int n;
int b[1010], x[1010], y[1010];
vector<Edge> edge[1010];

pair<int, int> d[1010];
bool used[1010];
vi ans;

void dijkstra(int s){
	rep(i, 1010){
		d[i] = mp(INF, -1);
		used[i] = false;
	}
	d[s].fi = 0;
	priority_queue<pii, vector<pii>, greater<pii> > q;
	pii p;
	q.push(mp(0, s));
	int from, to, cost;
	while(!q.empty()){
		p = q.top(); q.pop();
		from = p.se;
		//cost = p.fi;
		cost = d[from].fi;
		used[from] = true;
		for(int i = 0; i < edge[from].size(); i++){
			to = edge[from][i].t;
			if(used[to]) continue;
			if(d[to].fi > cost+edge[from][i].c){
				d[to].fi = cost+edge[from][i].c;
				d[to].se = from;
				q.push(mp(d[to].fi, to));
			}
		}
	}
}

int main(){
	int m, dx, dy;
	while(cin>>n && n){
		//cout<<n<<endl;
		rep(i, 1010){
			b[i]=x[i]=y[i] = -1;
			d[i] = mp(INF, -1);
			used[i] = false;
			edge[i].clear();
		}
		rep(i, n) cin>>b[i]>>x[i]>>y[i];
		for(int i = 0; i < 1010; i++){
			if(b[i] == -1 || x[i] == -1 || y[i]== -1) continue;
			for(int j = i + 1; j < 1010; j++){
				if(b[j] == -1 || x[j] == -1 || y[j] == -1) continue;
				dx = x[i]-x[j];
				dy = y[i]-y[j];
				if(dx*dx+dy*dy>2500)continue;
				edge[b[i]].push_back(Edge(b[j], dx*dx+dy*dy));
				edge[b[j]].push_back(Edge(b[i], dx*dx+dy*dy));
			}
		}
		//cout<<edge[1][0].t<<" "<<edge[1][0].c<<endl;
		//cout<<edge[2][0].t<<" "<<edge[2][0].c<<endl;

		cin>>m;
		rep(i, m){
			int s, g;
			cin>>s>>g;
			//cout<<s<<" "<<g<<endl;
			dijkstra(s);
			if(d[g].fi==INF) {
				cout<<"NA"<<endl;
				continue;
			}
			ans.clear();
			//bool usedG[1010]={};
			while(1){
				ans.pb(g);
				if(g == s /*|| g == -1*/) break;
				//usedG[g] = true;
				g = d[g].se;
				//if(usedG[g]) break;
				//cout<<"  "<<g<<endl;
			}
			//while(ans.size()> 0 && ans.back()==-1) ans.pop_back();
			reverse(all(ans));
			rep(j, ans.size()){
				if(j != 0) cout<<" ";
				cout<<ans[j];
			}
			cout<<endl;
		}
	}
}

C++: #include<iostream>
#include<cmath>
#include<vector>
#include<cstdlib>
#include<algorithm>
#define INF 1000000000

using namespace std;

void init(int);
int find(int);
void unite(int,int);
bool same(int,int);
void dijkstra(int);
vector<int>get_path(int);

int par[1001],rank[1001];
int V,prev[1001];
double cost[1001][1001],d[1001];
bool used[1001];

int main(void){

  int b[1001],m,s[1001],g[1001];
  double x[1001],y[1001];
  while(cin >> V,V){
    for(int i=0;i<V;i++){
      cin >> b[i] >> x[i] >> y[i];
    }

    cin >> m;
    for(int i=0;i<m;i++){
      cin>> s[i] >> g[i];
    }

    init(V);

    for(int i=0;i<=V;i++)
      for(int j=0;j<=V;j++)
	cost[i][j]=INF;

    for(int i=0;i<V;i++){
      for(int j=0;j<V;j++){
	if(i!=j){
	  double a=sqrt(pow(x[i]-x[j],2)+pow(y[i]-y[j],2));
	  if(a<=50.){
	    cost[b[i]][b[j]]=cost[b[j]][b[i]]=a;
	    unite(b[i],b[j]);
	  }
	}
      }
    }

    for(int i=0;i<m;i++){
      if(!same(s[i],g[i])){
	cout << "NA" << endl;
      }
      else {
	dijkstra(s[i]);
	vector<int>p=get_path(g[i]);
	for(int j=0;j<p.size();j++){
	  cout << p[j];
	  if(j!=p.size()-1)cout <<" ";
	  else cout << endl;
	}
      }
      
    }

  }

  return 0;
}

void init(int n){
  for(int i=0;i<n;i++){
    par[i]=i;
    rank[i]=0;
  }
}

int find(int x){
  if(par[x]==x)return x;
  else return par[x]=find(par[x]);
}

void unite(int x,int y){
  x=find(x);
  y=find(y);
  if(x==y)return;

  if(rank[x]<rank[y])par[x]=y;
  else{
    par[y]=x;
    if(rank[x]==rank[y])rank[x]++;
  }
}

bool same(int x,int y){
  return find(x)==find(y);
}

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

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

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

    for(int u=1;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;
}