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<algorithm>
#include<cmath>
#include<vector>
#define F first
#define S second
#define REP(i,s,n) for(int i=s;i<n;i++)
#define rep(i,n) REP(i,0,n)
#define EPS 1e-10
using namespace std;
struct P{
  int x,y;
  P (int x=0,int y=0):x(x),y(y){}
  P operator + (P p){return P(x+p.x,y+p.y);}
  P operator - (P p){return P(x-p.x,y-p.y);}
  P operator * (P p){return P(x*p.x,y*p.y);}
  P operator / (P p){return P(x/p.x,y/p.y);}

};

typedef pair<int,P> info;
int s,g;
double cost[1100][1100];
int n,m;
static const int INF = 1<<25;
void Init(){
  rep(i,1100){
    rep(j,1100){
      cost[j][i] = i==j?0:INF;
    }
  }
}

double norm(P p){
  return p.x*p.x+p.y*p.y;
}

double abs(P p){
  return sqrt(norm(p));
}

int prev[1100];
int d[1100];
bool used[1100];

void display(int num){
  for(int i=1;i<=num;i++){
    for(int j=1;j<=num;j++){
      printf("%4.0f ",cost[i][j]);
    }
    cout << endl;
  }
}


void dijkstra(){
  for(int i=0;i<1100;i++){
    d[i] = INF;
    used[i] = false;
    prev[i] = -1;
  }
  d[s] = 0;

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

    if(v == -1)break;
    used[v] = true;
    for(int i=1;i<=n;i++){
      if(d[i] > d[v]+cost[v][i]){
	d[i] = d[v]+cost[v][i];
	prev[i] = 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(){

  vector<info> vec;
  vector<int> _path;
  int b,x,y;
  info insert;
  while(cin >> n && n){
  Init();
    vec.clear();
    rep(i,n){
      cin >> b >> x >> y;
      insert.F = b;
      insert.S.x = x;insert.S.y = y;      
      vec.push_back(insert);
    }
    rep(i,n){
      rep(j,n){
	if(i == j)continue;
	double val = abs(vec[i].S-vec[j].S);
	if(val < 50+EPS){
	  cost[vec[i].F][vec[j].F] = cost[vec[j].F][vec[i].F] = val;
	}
      }
    }  

    cin >> m;
    rep(i,m){
      _path.clear();
      cin >> s >> g;
      dijkstra();
      _path = get_path(g);
      if(_path.size() == 1)cout << "NA" << endl;
      else{
	for(int i=0;i<_path.size();i++){
	  cout << _path[i];
	  i==_path.size()-1?cout << endl:cout << " ";
	}
      }
     
    }


  }



  return 0;
}

C++: #include <iostream>
#include <cmath>
using namespace std;

int x[1001], y[1001];
bool v[1001];
int p[1001];
double d[1001];
double edge[1001][1001];
int INF = (1 << 20);

void compute(int i, int j) {
  double temp = sqrt(((double)x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]));
  if (temp <= 50) edge[i][j] = temp;
}

void dijkstra(int s, int g, int n) {
  int mn,hozon,b, cnt = 0;
  int a[1001];

  // init
  
  for(int i = 0; i <= 1000; i++) {
    v[i] = false;
    p[i] = 0;
    d[i] = INF;
    a[i] = 0;
  }
  
  //cout << "init: " << v[1] << " " << p[5] << " " << d[7] << " " << a[8] << endl;

  //cout << "dijkstra in" << endl;
  d[s] = 0;

  for(;;) {
    mn = INF;

    //tmp=hozon;
    for(int i = 1; i <= 1000; i++) {
      if(mn > d[i] && !v[i]) {
	mn = d[i];
	hozon = i;
      }
    }
    //via[hozon]=tmp;
    if(mn == INF) break;

    v[hozon] = true;
    
    for(int j = 1; j <= 1000; j++) {
      if(edge[hozon][j]==INF)continue;
      if(d[j] > d[hozon] + edge[hozon][j] && !v[j]) {
	//if(hozon==19)cout<<j<<" "<<d[j]<<" "<<edge[hozon][j]<<endl;
	d[j] = edge[hozon][j] + d[hozon];
	p[j] = hozon;
	//cout<<p[j]<<" "<<j<<endl;                    1657 2225 3872
      }
    }
  }
  if(d[g] == INF) {
    cout << "NA" << endl;
  } else {
    b = p[g];// cout << "goal's p: " << p[g] << endl;   842 1800 900 3542
    while(1){
      // cout << "test" << endl;
      if (b == s){
	a[cnt++]=b;
	break;
      }
      a[cnt++] = b;
      b = p[b];
    }
    
    for(int i = cnt-1; i >= 0; i--) {
      cout << a[i] << " ";
    }
    cout <<g<< endl;
  }
}

int main (void) {
  int s, g;
  int n;
  int b, m;

  while(1) {
    
    cin >> n; if (n == 0) break;
    
    for(int i = 1; i <= n; i++) {
      cin >> b;
      cin >> x[b] >> y[b];
    }
    
    for(int i = 1; i <= 1000; i++) {
      for(int j = 1; j <= 1000; j++) {
	edge[i][j] = INF;
	if(i != j) compute(i, j);
      }
    }
    
    cin >> m; //cout << "m: " << m << endl;
    
    for(int i = 1; i <= m; i++) {
      cin >> s >> g;
      dijkstra(s, g, n);
    }
    
  }
  
  return 0;
}