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<algorithm>
#include<queue>
#include<vector>
#include<map>
#include<cmath>
#include<queue>
using namespace std;
typedef pair< double , int > P;
typedef pair< int , P > Pii;
#define reps(i,b,n) for(int i = b ; i < n ; ++i )
#define rep(i,n) reps(i,0,n)
#define INF 10000000
#define fr first
#define sc second
#define EPS (1e-10)
double getdis(int x1,int y1,int x2,int y2){return sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));}

int n,s,g;
double d[5001],dis;
int prev[5001];
struct edge{
  int to;
  double cost;
  edge(){}
  edge(int to,double cost):to(to),cost(cost){};
};
vector< vector< edge > > info;
vector<int> dijkstra(){
  vector<int> ans;
  fill_n(d,5001,INF),fill_n(prev,5001,-1);
  priority_queue<P,vector<P>,greater<P> > que;
  que.push(P(0.0,s));
  d[s] = 0.0;
  while(!que.empty()){
    P p = que.top();
    que.pop();
    double dis = p.fr;
    int now = p.sc;
    if(now == g){
      ans.push_back(g);
      int furuwara = g;
      while(furuwara != s){
        furuwara = prev[furuwara];
        ans.push_back(furuwara);
      }
      break;
    }
    rep(i,info[now].size()){
      edge e = info[now][i];
      if(d[now] + e.cost < d[e.to]){
        d[e.to] = d[now] + e.cost;
        que.push(P(d[e.to],e.to));
        prev[e.to] = now;
      }
    }
  }
  return ans;
}
int main(){
  while(cin >> n , n){
    int id[n],x[n],y[n],m;
    rep(i,n) cin >> id[i] >> x[i] >> y[i];
    info.resize(n + 1);
    rep(i,n) rep(j,n){
      if((dis = getdis(x[i],y[i],x[j],y[j])) <= 50.0){
        info[id[i]].push_back(edge(id[j],dis));
      }
    }
    cin >> m;
    while(m--){
      cin >> s >> g;
      vector<int> ans = dijkstra();
      if(ans.empty()) cout << "NA";
      else rep(i,ans.size()) cout << ( i ? " " : "" ) << ans[ans.size()-1-i];
      cout << endl;
    }
    info.clear();
  }
}

C++: #include <iostream>
#include <sstream>
#include <map>
#include <queue>
#include <cmath>
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;
int n, m;
int b[size], x[size], y[size];
map <int, int> cor;
bool path[size][size];
double cost[size][size];
double min_cost[size][size];
int con[size][size];
int concnt[size];

// <
bool big_equal( double a, double b )
{
    if ( a < b ) return true;
    return fabs( a - b ) < eps;
}

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

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

    ostringstream os;
    QUEUE Q;
    PPV start_node( PDI( 0.0, start ), vector<int>() );
    Q.push( start_node );

    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 );

        if ( number == g_ ) {
            for ( vector <int> ::iterator it = route.begin(); it != route.end(); it++ ) {
                os << *it;
                if ( it + 1 != route.end() ) os << " ";
            }
            break;
        }

        for ( int i = 0; i < concnt[ind]; i++ ) {
            int next_ind = con[ind][i];
            double next_c = c + cost[ind][next_ind];
            if ( min_cost[ind][next_ind] < -0.5 || big_equal( min_cost[ind][next_ind], next_c ) ) {
                min_cost[ind][next_ind] = next_c;
                PPV next_node( PDI( next_c, next_ind ), route );
                Q.push( next_node );
            }
        }

    }

    return os.str();
}

int main( void )
{
    while ( cin >> n && n ) {
        // init
        for ( int i = 0; i < n; i++ ) {
            for ( int j = 0; j < n; j++ ) {
                path[i][j] = false;
                min_cost[i][j] = -100.0;
            }
            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 = i+1; j < n; j++ ) {
                cost[i][j] = cost[j][i] = getDistance( x[i], y[i], x[j], y[j] );
            }
        }

        // proc
        for ( int i = 0; i < n; i++ ) {
            for ( int j = i+1; j < n; j++ ) {
                if ( big_equal( cost[i][j], 50.0 ) ) {
                    path[i][j] = path[j][i] = true;
                    con[i][concnt[i]] = j;
                    concnt[i]++;
                    con[j][concnt[j]] = i;
                    concnt[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] ) continue;
                    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;
}