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<cstdio>
#include<cfloat>
#include<cmath>
#include<vector>
#include<queue>
#include<utility>
#include<algorithm>
#include<functional>
using namespace std;

const int MAX_N = 1001;
const double EPS = 1e-6;

typedef pair<double, int>P;	//<distance, index>
vector<vector<P> >edge(MAX_N);

#define Square(x) ((x)*(x))

double Distance(int x1, int x2, int y1, int y2)
{
	return sqrt((double)Square(x1-x2)+Square(y1-y2));
}

vector<int> Solve(int s, int g)
{
	//_CNXg@ÅA¸_s©ç¼ÌSÄÌ¸_ÜÅKvÈÅZ£ðßé
	double dist[MAX_N];	//dist[i] := ¸_iÉ½Çè­ÜÅÉKvÈÅZ£
	fill(dist, dist+MAX_N, DBL_MAX);

	typedef pair<double, int> P;	//<»Ì¸_ÜÅÌ£,¡¢é¸_>
	priority_queue<P, vector<P>, greater<P> >q;
	q.push(P(0,s));
	while(!q.empty())
	{
		P p(q.top());
		q.pop();

		double d = p.first;
		int id = p.second;
		if(dist[id] <= d)
			continue;
		dist[id] = d;

		for(int i=0; i<edge[id].size(); ++i)
			q.push(P(d+edge[id][i].first, edge[id][i].second));
	}

	//Bs\Å é
	if(dist[g] == DBL_MAX)
		return vector<int>();

	//oHðAS[©çX^[gÖü¯ÄAtÉ³
	vector<int> res;
	res.push_back(g);
	for(int id=g; id!=s; )
	{
		for(int i=0; i<edge[id].size(); ++i)
		{
			if( (dist[edge[id][i].second]+edge[id][i].first - dist[id]) < EPS )
			{
				id = edge[id][i].second;
				res.push_back(id);
				break;
			}
		}
	}
	return res;
}

int main()
{
	int n,b,x[MAX_N],y[MAX_N],m,s,g;
	int i,j;
	vector<int>id;
	while(scanf("%d",&n),n)
	{
		id.clear();
		for(i=0; i<n; ++i)
			edge[i].clear();
		for(i=0; i<n; ++i)
		{
			scanf("%d",&b);
			scanf("%d%d",&x[b],&y[b]);
			id.push_back(b);
		}
		
		//Ú®Â\È¸_¯mÉÓð\é
		for(i=0; i<id.size(); ++i)
		{
			for(j=i+1; j<id.size(); ++j)
			{
				int i1 = id[i];
				int i2 = id[j];
				double distance = Distance(x[i1],x[i2],y[i1],y[i2]);
				if( distance<=50 )
				{
					edge[i1].push_back(P(distance,i2));
					edge[i2].push_back(P(distance,i1));
				}
			}
		}

		vector<int> res;
		scanf("%d",&m);
		while(m--)
		{
			scanf("%d%d",&s,&g);
			res = Solve(s,g);
			if(res.empty())
				puts("NA");
			else
			{
				for(int i=res.size()-1; i>=0; --i)
					printf("%d%c",res[i], (i?' ':'\n'));
			}
		}
	}
	return 0;
}

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
map <int, int> T; // index to number;
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();

        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;

        // goal
        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();
        }

        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;
}