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++: // AOJ 0155
// URL: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=0155

#include <iostream>
#include <sstream>
#include <map>
#include <queue>
#include <cmath>
#include <algorithm>
using namespace std;

typedef pair <double, int> PDI;
typedef pair <PDI, vector <int> > PPV;
typedef priority_queue <PPV, vector<PPV>, greater <PPV> > QUEUE;

const double eps = 1e-9;
const int size = 1001;
const string NA = "NA";
int n, m;
int b[size], x[size], y[size];
map <int, int> cor; // number to index
bool path[size][size];
double cost[size][size];
double min_cost[size];
int con[size][size]; // connect
int concnt[size]; // connect count

double get_distance( int x1, int y1, int x2, int y2 )
{
    double x = ( x2 - x1 ), y = ( y2 - y1 );
    return sqrt( x * x + y * y );
}

// dijkstra
string solve( int s_, int g_ )
{
    int start = cor[s_], goal = cor[g_];
    if ( !path[start][goal] ) return NA;

    // init
    ostringstream os;
    QUEUE Q;
    PPV start_node( PDI( 0.0, start ), vector<int>() );
    Q.push( start_node );
    min_cost[start] = 0.0;
    bool used[size] = {false};

    // proc
    while ( !Q.empty() ) {
        PPV node = Q.top();
        Q.pop();

        // proc init
        double c = node.first.first;
        int ind = node.first.second;
        int number = b[ind];
        vector <int> route = node.second;
        route.push_back( number );
        used[ind] = true;

        // cout << ind << "(" << number << "), c=" << c << ", route.size=" << route.size() << endl;

        // goal, output
        if ( number == g_ ) {
            for ( vector <int> ::iterator it = route.begin(); it != route.end(); it++ ) {
                os << *it;
                if ( it + 1 != route.end() ) os << " ";
            }
            return os.str();
        }

        // move
        for ( int i = 0; i < concnt[ind]; i++ ) {
            int next_ind = con[ind][i];
            if ( used[next_ind] ) continue;
            int next_number = b[next_ind];
            double next_c = c + cost[ind][next_ind];
            if ( next_c < min_cost[next_ind] ) {
                min_cost[next_ind] = next_c;
                PPV next_node( PDI( next_c, next_ind ), route );
                Q.push( next_node );
            }
        }
    }

    return NA;
}

int main( void )
{
    while ( cin >> n && n ) {
        // init
        cor.clear();
        for ( int i = 0; i < n; i++ ) {
            min_cost[i] = (double)(1<<24);
            for ( int j = 0; j < n; j++ ) {
                path[i][j] = false;
            }
            concnt[i] = 0;
        }

        // input
        for ( int i = 0; i < n; i++ ) {
            cin >> b[i] >> x[i] >> y[i];
            cor[b[i]] = i;
        }

        for ( int i = 0; i < n; i++ ) {
            for ( int j = 0; j < n; j++ ) {
                if ( i == j ) continue;
                cost[i][j] = get_distance( x[i], y[i], x[j], y[j] );
            }
        }

        // proc
        for ( int i = 0; i < n; i++ ) {
            for ( int j = 0; j < n; j++ ) {
                if ( i == j ) continue;
                if ( cost[i][j] < 50.0 + eps ) {
                    path[i][j] = true;
                    con[i][concnt[i]++] = j;
                }
            }
        }

        // floyd-warshall
        for ( int k = 0; k < n; k++ ) {
            for ( int i = 0; i < n; i++ ) {
                for ( int j = 0; j < n; j++ ) {
                    if ( i == k || k == j || j == i ) continue;
                    if ( path[i][k] && path[k][j] ) path[i][j] = true;
                }
            }
        }

        // query
        cin >> m;
        for ( int i = 0; i < m; i++ ) {
            int s, t;
            cin >> s >> t;
            cout << solve( s, t ) << endl;
        }
    }
    return 0;
}

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;
}

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;
}