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 unsigned long long ull;

#define loop(i,a,b) for(int i=(a);i<ull(b);++i)
#define rep(i,n) loop(i,0,n)

#define MAX 1010

const double eps = 1e-10;
const double pi  = acos(-1.0);
const double inf = (int)1e8;

int n;
double cost[MAX][MAX];
int to_id[MAX];
int to_num[MAX];
vector<pair<int, int> > vv;

int prev[MAX];
double d[MAX];
bool used[MAX];
int V;

void dijkstra(int s){
    fill(d, d+V, inf);
    fill(used, used+V, false);
    fill(prev, prev+V, -1);
    d[s] = 0;

    while(true){
        int v = -1;
        for(int u=0; u < V; u++){
            if(!used[u] && (v==-1 || d[u] < d[v])) v = u;
        }

        if(v == -1)break;
        used[v] = true;

        for(int u=0; u < V; u++){
            if(d[u] > d[v] + cost[v][u]){
                d[u] = d[v] + cost[v][u];
                prev[u] = v;
            }
        }
    }
}

vector<int> get_path(int t){
    vector<int> path;
    for(; t != -1; t = prev[t]) path.push_back(t);
    reverse(path.begin(), path.end());
    return path;
}

int main(){
    while(cin >> n, n){
        V = n;
        vv.clear();
        rep(i, n){
            int b, x, y;
            cin >> b >> x >> y;
            to_id[i] = b; to_num[b] = i; vv.push_back(make_pair(x, y));
        }
        rep(i, n)rep(j, n){
            if(i == j) {cost[i][j] = inf; continue;}
            double d = abs(sqrt(pow(vv[i].first-vv[j].first, 2)+pow(vv[i].second-vv[j].second, 2)));
            if(d-eps <= 50.0){/*cout << i << " " << j << " " << d << endl;*/ cost[i][j] = d;}
            else cost[i][j] = inf;
        }
        int m;
        cin >> m;
        rep(i, m){
            int s, g;
            cin >> s >> g; s; g;
            dijkstra(to_num[s]);
            vector<int> p = get_path(to_num[g]);

            if(p.size() == 1) cout << "NA" << endl;
            else {
                rep(j, p.size()) cout << (j==0?"":" ") << to_id[p[j]];
                cout << endl;
            }
        }
    }
}

C++: #include <cstring>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <queue>
#include <vector>
using namespace std;
const int MAX_N = 1000;
int n;
int s, g;
double edges[MAX_N + 1][MAX_N + 1];
int visited[MAX_N + 1];
vector<int> route;

bool shotestPath() {
	memset(visited, -1, sizeof(visited));
	typedef pair<double, pair<int, int> > P;
	priority_queue<P, vector<P>, greater<P> > que;
	que.push(make_pair(0., make_pair(s, 0)));
	while (!que.empty()) {
		P current = que.top();
		que.pop();
		const double cost = current.first;
		const int pos = current.second.first;
		const int pre = current.second.second;
		if (visited[pos] != -1) continue;
		visited[pos] = pre;
		if (pos == g) {
			return true;
		}
		for (int i = 1; i <= n; i++) {
			if (edges[pos][i] >= 0.) {
				que.push(make_pair(cost + edges[pos][i], make_pair(i, pos)));
			}
		}
	}
	return false;
}

void buildRoute(int p) {
	if (p == 0) return;
	route.push_back(p);
	buildRoute(visited[p]);
}

void solve() {
	if (shotestPath()) {
		route.clear();
		buildRoute(g);
		vector<int>::reverse_iterator it = route.rbegin();
		cout << (*it);
		for (++it; it != route.rend(); ++it) {
			cout << ' ' << (*it);
		}
		cout << endl;
	}
	else {
		cout << "NA" << endl;
	}
}

int main () {
	while (cin >> n, n) {
		double x[n], y[n];
		for (int i = 0; i < n; i++) {
			int b;
			cin >> b;
			cin >> x[b] >> y[b];
		}
		for (int i = 1; i <= n; i++) {
			for (int j = i + 1; j <= n; j++) {
				double w = x[i] - x[j];
				double h = y[i] - y[j];
				double d = w * w + h * h;
				if (d <= 50. * 50.) {
					edges[i][j] = edges[j][i] = sqrt(d);
				}
				else {
					edges[i][j] = edges[j][i] = -1.;
				}
			}
		}
		int m;
		cin >> m;
		for (int i = 0; i < m; i++) {
			cin >> s >> g;
			solve();
		}
	}
	return 0;
}

C++: #include <iostream>
#include <cmath>
#include <queue>
#include <algorithm>
#include <memory.h>
#include <vector>
#include <map>
#include <cstdlib>
#include <ctime>
using namespace std;

#define rep(i, n) for(int i = 0; i < n; i++)
typedef pair<double, int> state;
const int CLK = CLOCKS_PER_SEC;

int s, g;
double memo[100];
int pre[100];
int name[100];
double x[100];
double y[100];

map<int, int> nums;

double dis(int i, int j){
  return sqrt((x[i] - x[j])*(x[i] - x[j]) + (y[i] - y[j])*(y[i] - y[j]));
}

double heuristics(int v){
  return dis(v, nums[g]);
}

int main(){
  int n, m;
  int b;
  while(cin >> n &&n){
    nums.clear();
    rep(i, n){
      cin >> b >> x[i] >> y[i];
      name[i] = b;
      nums[b] = i;
    }
    cin >> m;
    rep(i, m){
      memset(pre, -1, sizeof(pre));
      fill(memo, memo + 100, 1e10);
      cin >> s >> g;
      memo[nums[s]] = heuristics(nums[s]);
      priority_queue<state, vector<state>, greater<state> > que;
      que.push(state(heuristics(nums[s]), nums[s]));
      while(!que.empty()){
		state st = que.top();
	que.pop();
	int v = st.second;
	double fcost = st.first;
	double gcost = fcost - heuristics(v);
	if(name[v] == g){
	  break;
	}
	if(fcost > memo[v]) continue;
	rep(i, n){
	  double d = dis(v, i);
	  if(d > 50.0) continue;
	  if(memo[i] > gcost + d + heuristics(i)){
	    memo[i] = gcost + d + heuristics(i);
	    pre[i] = v;
	    que.push(state(memo[i], i));
	  }
	}
      }
      if(pre[nums[g]] == -1 && s != g){
	cout << "NA" << endl;
      }else{
	vector<int> res;
	int v = nums[g];
	res.push_back(v);
	/*
	while(pre[v] >= 0){
	  v = pre[v];
	  res.push_back(v);
	}
	*/
	rep(i, (int)res.size()){
	  if(i != 0) cout << " " ;
	  cout << name[res[res.size() - 1 - i]];
	}
	cout << endl;
      }
    }
  }
  
  return 0;
}