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 <bits/stdc++.h>
using namespace std;
typedef long long ll;

double x[100];
double y[100];

typedef double W;

const W INF = 1e9;

struct edge {
	int to;
	W cost;
};
typedef pair<W, int> P;
typedef vector<vector <edge > > Graph;


void dijkstra(int s, const Graph& G, vector<W>& d, vector<int>& prev) {
	priority_queue< P, vector<P>, greater<P> > que;
	fill(d.begin(), d.end(), INF);
	fill(prev.begin(), prev.end(), -1);

	d[s] = 0;
	que.push(P(0, s));
	while(!que.empty()) {
		P p = que.top();
		que.pop();
		int v = p.second;
		if(d[v] < p.first) continue;
		for(int i = 0; i < G[v].size(); i++) {
			edge e = G[v][i];
			if(d[e.to] > d[v] + e.cost) {
				prev[e.to] = v;
				d[e.to] = d[v] + e.cost;
				que.push(P(d[e.to], e.to));
			}
		}
	}
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n, m;
	while(cin >> n, n) {
		for(int i = 0; i < n; i++) {
			int b;
			double xx, yy;
			cin >> b >> xx >> yy;
			b--;
			x[b] = xx, y[b] = yy;
		}

		Graph G(n);
		for(int i = 0; i < n; i++) {
			for(int j = i + 1; j < n; j++) {
				double dx = x[i] - x[j];
				double dy = y[i] - y[j];
				double dist = sqrt(dx * dx + dy * dy);
				if(dist <= 50) {
					G[i].push_back({ j, dist });
					G[j].push_back({ i, dist });
				}
			}
		}

		cin >> m;
		vector<double> d(n);
		vector<int> prev(n);
		for(int i = 0; i < m; i++) {
			int s, g;
			cin >> s >> g;
			s--, g--;
			dijkstra(s, G, d, prev);
			if(d[g] == INF) {
				cout << "NA" << endl;
			}
			else {
				vector<int> ans;
				int v = g;
				ans.push_back(g);
				while(v != s) {
					v = prev[v];
					ans.push_back(v);
				}
				for(int j = ans.size() - 1; j >= 0; j--) {
					cout << ans[j] + 1;
					if(j != 0) cout << " ";
					else cout << endl;
				}
			}
		}

	}
}

C++: #include <functional>
#include <algorithm>
#include <iostream>
#include <numeric>
#include <iomanip>
#include <utility>
#include <cstdlib>
#include <sstream>
#include <bitset>
#include <vector>
#include <cstdio>
#include <ctime>
#include <queue>
#include <deque>
#include <cmath>
#include <stack>
#include <list>
#include <map>
#include <set>

using namespace std;

typedef vector<int> vi;
typedef pair<int,int> pii;
typedef long long ll;

#define dump(x)  cerr << #x << " = " << (x) << endl
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(a)  (a).begin(),(a).end()
#define pb push_back


int main() {
    int n;
    while(cin>>n){
        if(n==0)break;
        
        int b[1000]={},x[1000]={},y[1000]={};
        rep(i,n){
            cin>>b[i]>>x[i]>>y[i];
            b[i]--;
        }
        
        float data[1000][1000]={};
        rep(i,n) rep(j,n) data[i][j]=99999999;
        int prev[1000][1000]={};
        
        rep(i,n){
            rep(j,n){
                double res=sqrt( (x[i]-x[j]) * (x[i]-x[j])  +  (y[i]-y[j]) * (y[i]-y[j]) );
                if(res<=50){
                    data[i][j]=res;
                    prev[i][j]=i;
                }
            }
        }
        
        rep(k,n){
            rep(i,n){
                rep(j,n){
                    if( data[i][k]+data[k][j] < data[i][j] ){
                        data[i][j] = data[i][k]+data[k][j];
                        prev[i][j]=prev[k][j];
                    }
                    data[i][j]=min( data[i][k]+data[k][j] , data[i][j] );
                }
            }
        }
        
        int m;
        cin>>m;
        
        int s,g;
        rep(i,m){
            cin>>s>>g;
            s--,g--;
            if(data[s][g]!=99999999){
                stack<int> ans;
                int pre=g;
                while(pre!=s){
                    ans.push(pre);
                    pre=prev[s][pre];
                }
                cout<<s+1;
                while(ans.size()){
                    cout<<" "<<ans.top()+1;
                    ans.pop();
                }
                cout<<endl;
            }
            else cout<<"NA"<<endl;
        }
    }
    return 0;
}