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 <int, vector <int> > PIV;
typedef pair <double, PIV > PDV;
typedef priority_queue <PDV, vector<PDV>, greater <PDV> > QUEUE;

const double eps = 1e-12;
const double inf = (double)(1<<24);
const int size = 1001;
const string NA = "NA";
int n, m;
int b[size];
double 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 fabs( 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;
    PDV start_node( 0.0, PIV( start , vector<int>() ) );
    Q.push( start_node );
    min_cost[start] = 0.0;

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

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

        // 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];
            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;
                PDV next_node( next_c, PIV( 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++ ) {
            concnt[i] = 0;
            for ( int j = 0; j < n; j++ ) {
                cost[i][j] = inf;
                path[i][j] = false;
            }
        }

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

        // proc
        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] );
            }
        }

        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++ ) {
            for ( int j = 0; j < n; j++ ) min_cost[j] = inf;
            int s, t;
            cin >> s >> t;
            cout << solve( s, t ) << endl;
        }
    }
    return 0;
}

C++: #include<iostream>
#include<vector>
#include<set>
#include<stack>
#include<cmath>
#include<climits>
#include<cfloat>
using namespace std;

#define INF DBL_MAX
#define NONE INT_MAX
#define MAX 50.0

struct Point{double x,y;};
double dist(Point a,Point b){return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));}

int main()
{
  int n,b,m,s,g;
  double x,y,M[1000][1000];
  while(cin>>n,n){
    vector<Point>building(n);
    for(int i=0;i<n;i++){
      cin>>b>>x>>y;
      b--;
      Point p={x,y};
      building[b]=p;
    }
    for(int i=0;i<n;i++)for(int j=0;j<n;j++){
      double t=dist(building[i],building[j]);
      if(i==j)M[i][j]=INF;
      else if(t>50.0)M[i][j]=INF;
      else M[i][j]=t;
    }

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

      set<int>used;
      set<int>::iterator it;
      vector<double>d(n,INF);
      vector<int>p(n,NONE);
      d[s]=0;
      used.insert(s);
      while(used.size()!=n){
	bool end=true;
	double min=INF;
	int next,prev;
	for(int i=0;i<n;i++){
	  if(used.count(i))continue;
	  for(it=used.begin();it!=used.end();it++){
	    if(d[*it]+M[*it][i]<min){
	      min=d[*it]+M[*it][i];
	      next=i;
	      prev=*it;
	    }
	  }
	  if(min!=INF)end=false;
	}
	if(end)break;
	used.insert(next);
	p[next]=prev;
	d[next]=min;
      }

      stack<int>path;
      int t=g;
      while(p[t]!=NONE){
	path.push(p[t]);
	t=p[t];
      }
      if(path.size()&&path.top()==s){
	while(path.size()){
	  cout<<path.top()+1<<" ";
	  path.pop();
	}
	cout<<g+1<<endl;
      }else{
	puts("NA");
      }
    }
  }
}