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){
		int 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] = 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 <int> 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(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 <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <cfloat>
#include <climits>
#include <ctime>
#include <cassert>
#include <numeric>
#include <fstream>
#include <functional>
#include <bitset>

using namespace std;
#define int long long int
const double INF = 1e16;
const int MOD = 1000000007;

int di[] = {-1, 0, 1, 0, -1, 1, 1, -1};
int dj[] = {0, 1, 0, -1, 1, 1, -1, -1};

signed main(){
    

    while(1){
    int n; cin >> n;
    if(!n) break;
    vector<double> x(n);
    vector<double> y(n);
    map<int, int> mp;
    map<int, int> inv;
    for(int i = 0; i < n; i++){
        int b;
        cin >> b >> x[i] >> y[i];
        b--;
        mp[i] = b;
        inv[b] = i;
    }
    vector<vector<double> > g(n, vector<double> (n, INF));
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            double dist = sqrt((x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]));
            if(dist <= 50.0 + 1e-4) g[i][j] = dist;
        }
    }

    vector<vector<double> > org(n, vector<double> (n));
    for(int i = 0; i < n; i++) for(int j = 0; j < n; j++) org[i][j] = g[i][j];
    
    /*
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            cout << g[i][j] << " ";
        }
        cout << endl;
    }*/

    for(int k = 0; k < n; k++){
        for(int i = 0; i < n; i++){
            for(int j = 0; j < n; j++){
                g[i][j] = min(g[i][j], g[i][k] + g[j][k]);
            }
        }
    }

    int m; cin >> m;

    for(int i = 0; i < m; i++){
        int s, t; cin >> s >> t;
        s--;
        t--;
        s = inv[s];
        t = inv[t];

        int cur = s;
        vector<int> ans;
        ans.push_back(s);
        double D = g[s][t];
        vector<int> used(n, false);
        used[s] = true;
        
        if(g[s][t] == INF){
            cout << "NA" << endl;
            continue;
        }

        while(cur != t){
            
            for(int j = 0; j < n; j++){
                if(used[j]) continue;
                
                double val = org[cur][j] + g[s][cur] + g[j][t];
                if(D - 1e-4 <= val && val <= D + 1e-4){
                    ans.push_back(j);
                    cur = j;
                    used[cur] = true;
                    break;
                }
            }

        }

        for(int i = 0; i < (int)ans.size(); i++){
            if(i + 1 == ans.size()) cout << mp[ans[i]] + 1 << endl;
            else cout << mp[ans[i]] + 1 << " ";
        }
    }

    }   

    return 0;
}