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;
int main(){
	int n;
	while(cin >> n , n){
		double g[n][n];
		for(int i = 0; i < n; i++)
			for(int j = 0; j < n; j++)
				g[i][j] = 100000000;
		int b[n] , x[n] , y[n];
		for(int i = 0; i < n; i++)
			cin >> b[i] >> x[i] >> y[i];
		for(int i = 0; i < n; i++)
			for(int j = 0; j < n; j++){
				int xx = x[i] - x[j],
					   yy = y[i] - y[j];
				if(pow(xx , 2) + pow(yy , 2) <= 2500 && i != j)
					g[i][j] = g[j][i] = sqrt(pow(xx , 2) + pow(yy , 2));
			}
		int m;
		cin >> m;
		int s , go;
		for(int i = 0; i < m; i++){
			cin >> s >> go;
			s--; go--;
			vector <int> used(n,false);
			vector <int> gone(n,false);
			vector <double> dist(n,100000000);
			dist[s] = 0;
			gone[s] = 0;
			while(1){
				int va = -1;
				for(int j = 0; j < n; j++)
					if(used[j] == false && (va == -1 || dist[va] > dist[j]))
						va = j;
				if(va == -1)
					break;
				used[va] = true;
				for(int j = 0; j < n; j++){
					if(dist[j] >= dist[va] + g[va][j])
						gone[j] = va;
					dist[j] = min(dist[j] , dist[va] + g[va][j]);
				}
			}
			if(s == go)
				cout << s + 1 << " " << go + 1 << endl;
			else if(dist[go] == 100000000)
				cout << "NA" << endl;
			else{
				int kari = go;  // go == 21
				stack <int> out;
				while(1){
					out.push(gone[kari] + 1);
					kari = gone[kari];
					if(kari == s)
						break;
				}
				while(!out.empty()){
					cout << out.top() << " ";
					out.pop();
				}
				cout << go + 1 << endl;
			}
		}
	}
}

C++: #include <cstdio>
#include <iostream>
#include <string>
#include <vector>
#include <sstream>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <typeinfo>
#include <numeric>
#include <functional>
#include <unordered_map>
#include <bitset>
#include <stack>


using namespace std;
using ll = long long;
using ull = unsigned long long;

const ll INF = 1e16;
const ll MOD = 1e9 + 7;

#define REP(i, n) for(ll i = 0; i < n; i++)










using P = pair<double, ll>;

int main() {
    ll n;
    while(cin >> n, n){
        vector<ll> b(n);
        vector<double> x(n), y(n);
        REP(i, n){
            cin >> b[i] >> x[i] >> y[i];
            b[i]--;
        }
        
        vector<vector<P>> g(n);
        REP(i, n){
            REP(j, n){
                if(i == j) continue;
                
                double d = sqrt((x[j] - x[i]) * (x[j] - x[i]) + (y[j] - y[i]) * (y[j] - y[i]));
                if(d <= 50.0){
                    g[b[i]].push_back({d, b[j]});
                    g[b[j]].push_back({d, b[i]});
                }
            }
        }
        
        ll m;
        cin >> m;
        REP(i, m){
            ll S, G;
            cin >> S >> G;
            S--; G--;
            
            vector<double> dist(n, INF);
            dist[S] = 0;
            vector<ll> prev(n);
            priority_queue<P, vector<P>, greater<P>> que;
            que.push({0, S});
            while(!que.empty()){
                auto tmp = que.top(); que.pop();
                double d = tmp.first;
                ll now = tmp.second;
                if(dist[now] < d) continue;
                
                for(auto &x : g[now]){
                    double cost = d + x.first;
                    ll v = x.second;
                    if(dist[v] > cost){
                        dist[v] = cost;
                        prev[v] = now;
                        que.push({cost, v});
                    }
                }
            }
            
            if(dist[G] == INF){
                cout << "NA" << endl;
                continue;
            }
            
            vector<ll> ans;
            for(ll v = G; v != S; v = prev[v]){
                ans.push_back(v + 1);
            }
            ans.push_back(S + 1);
            reverse(ans.begin(), ans.end());
            REP(i, ans.size()){
                cout << ans[i] << " \n"[i == ans.size() - 1];
            }
        }
    }
}

C++: #include <iostream>
#include <cmath>
#define INF 1e+9
#define EPS 1e-9
using namespace std;

int main(){
	int n,b[100];
	double x[100],y[100];
	double cost[100][100];
	int next[100][100];
	while(cin >> n,n){
		for(int i = 0;i < n;i++){
			for(int j = 0;j < n;j++) {
				cost[i][j] = INF;
				next[i][j] = j;
			}
			cost[i][i] = 0;
		}
		for(int i = 0;i < n;i++) cin >> b[i] >> x[i] >> y[i];
		for(int i = 0;i < n;i++){
			for(int j = 0;j < n;j++){
				double d = (x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]);
				if(i != j && d <= 2500.0){
					cost[i][j] = 1;
					cost[j][i] = 1;
				}
			}
		}
		for(int k = 0;k < n;k++){
			for(int i = 0;i < n;i++){
				for(int j = 0;j < n;j++){
					if(cost[i][j] > cost[i][k] + cost[k][j]){
						cost[i][j] = cost[i][k] + cost[k][j];
						next[i][j] = next[i][k];
					}
				}
			}
		}
		int m;
		cin >> m;
		for(int i = 0;i < m;i++){
			int s,g,S,G;
			cin >> s >> g;
			for(int j = 0;j < n;j++){
				if(b[j] == s) S = j;
				if(b[j] == g) G = j;
			}
			if(cost[S][G] == INF){
				cout << "NA" << endl;
				continue;
			}
			while(S != G){
				cout << b[S] << " ";
				S = next[S][G];
			}
			cout << b[G] << endl;
		}
	}
	
	return 0;
}