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<queue>
#include<vector>
#include<cstring>
#include<functional>
using namespace std;
typedef pair<double, int> P;
priority_queue<P, vector<P>, greater<P>> Q;
#define MAX_N 1005
int x[MAX_N], y[MAX_N]; double dist[MAX_N];
vector<int>path[MAX_N]; vector<P>X[MAX_N];
void dijkstra(int a, int b) {
	memset(dist, 1e+9, sizeof(dist));
	for (int i = 0; i < MAX_N; i++) { path[i].clear(); }
	Q.push(make_pair(0.0, a)); dist[a] = 0; path[a].push_back(a);
	while (!Q.empty()) {
		pair<double, int>pa = Q.top(); Q.pop();
		double a1 = pa.first; int a2 = pa.second;
		for (int i = 0; i < X[a2].size(); i++) {
			int to = X[a2][i].second; double dis = X[a2][i].first;
			if (dist[to] > a1 + dis) {
				dist[to] = a1 + dis; path[to].clear();
				path[to] = path[a2]; path[to].push_back(to);
				Q.push(make_pair(dist[to], to));
			}
		}
	}
	if (path[b].size() == 0) { cout << "NA" << endl; }
	else {
		for (int i = 0; i < path[b].size(); i++) { if (i) { cout << ' '; } cout << path[b][i]; }
		cout << endl;
	}
}
int main() {
	int N, Q, s, g;
	while (true) {
		cin >> N; if (N == 0) { break; }
		for (int i = 0; i < N; i++) { cin >> x[i] >> y[i]; }
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				double dist2 = (x[i] - x[j])*(x[i] - x[j]) + (y[i] - y[j])*(y[i] - y[j]);
				if (dist2 <= 50.0) {
					X[i].push_back(make_pair(dist2, j));
				}
			}
		}
		cin >> Q; for (int i = 0; i < Q; i++) { cin >> s >> g; dijkstra(s, g); }
	}
	return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

using ll = long long;
using Pi = pair<int, int>;
using Pl = pair<ll, ll>;
using Ti = tuple<int, int, int>;
using Tl = tuple<ll, ll, ll>;

#define pb push_back
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
#define F first
#define S second
#define Get(t, i) get<(i)>((t))
#define all(v) (v).begin(), (v).end()
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define reps(i, f, n) for(int i = (int)(f); i < (int)(n); i++)
#define each(a, b) for(auto& a : b)
#define int long long

const int inf = 1 << 25;
const ll INF = 1LL << 55;

struct edge
{
  int to, cost;
  edge(){}
  edge(int to, int cost):to(to), cost(cost){}
};

int n;
vector< vector<edge> > graph;

void dijkstra(int s, int g)
{
  vector<int> min_cost(n, INF);
  vector<int> prevv(n, -1);
  priority_queue<Pl, vector<Pl>, greater<Pl> > que;
  que.push(Pl(0LL, s));
  min_cost[s] = 0LL;
  while(!que.empty()) {
    Pl p = que.top(); que.pop();
    if(p.S == g) break;
    if(min_cost[p.S] < p.F) continue;
    for(edge e : graph[p.S]) {
      if(e.cost + p.F < min_cost[e.to]) {
	min_cost[e.to] = e.cost + p.F;
	//cout << " " << p.S << " " << e.to << " " << e.cost << endl;
	prevv[e.to] = p.S;
	que.push(Pl(min_cost[e.to], e.to));
      }
    }
  }
  if(min_cost[g] == INF) {
    puts("NA");
    return;
  }
  //cout << min_cost[g] << endl;
  vector<int> ans;
  for(int v = g; v != -1; v = prevv[v]) {
    ans.push_back(v+1);
  }
  reverse(all(ans));
  for(int i = 0; i < ans.size(); i++) {
    if(i) cout << " ";
    cout << ans[i];
  }
  cout << endl;
}

int dist(Pl a, Pl b)
{
  return ((a.F-b.F)*(a.F-b.F) + (a.S-b.S)*(a.S-b.S));
}

signed main()
{
  while(cin >> n, n) {
    vector<Pl> pos(n);
    for(int i = 0; i < graph.size(); i++) graph[i].clear();
    graph.clear(); graph.resize(n);
    for(int i = 0; i < n; i++) {
      int b; cin >> b; b--;
      cin >> pos[b].F >> pos[b].S;
    }
    for(int i = 0; i < n; i++) {
      for(int j = i+1; j < n; j++) {
	if(dist(pos[i], pos[j]) <= 50LL*50LL) {
	  //cout << i+1 << " " << j+1 << " "<< pos[i].F << " " << pos[i].S << " " << pos[j].F << " "<< pos[j].S << " " << dist(pos[i], pos[j]) << endl;
	  graph[i].push_back(edge(j, 1));//dist(pos[i], pos[j])));
	  graph[j].push_back(edge(i, 1));//dist(pos[i], pos[j])));	  
	}
      }
    }
    int m; cin >> m;
    while(m--) {
      int s, g; cin >> s >> g;
      s--, g--;
      dijkstra(s, g);
    }
  }
  return 0;
}

C++: #include<cstdio>
#include<iostream>
#include<vector>
#include<algorithm>
#include<queue>
#include<stack>
using namespace std;

const double EPS = 1e-4;

struct Building{
	int x, y;
};

struct Edge{
	int to;
	double cost;
	Edge(){}
	Edge(const int &_to, const double &_cost){
		to = _to; cost = _cost;
	}
};

struct Data{
	int n;
	double cost;
	Data(){}
	Data(const int &_n, const double &_cost){
		n = _n; cost = _cost;
	}
	bool operator < (const Data &a) const{
		return cost > a.cost;
	}
};

double GetDistance(Building &b1, Building &b2){
	double dx = b1.x - b2.x, dy = b1.y - b2.y;
	return sqrt(dx*dx + dy*dy);
}

int main(){
	int N, M, B, S, G;

	while(cin >> N, N){
		Building v[1000];
		vector<Edge> e[1000];

		for(int i = 0; i < N; i++){
			cin >> B; B--;
			cin >> v[B].x >> v[B].y;
		}

		for(int i = 0; i < N; i++){
			for(int j = i+1; j < N; j++){
				double dist = GetDistance(v[i], v[j]);
				if(dist <= 50){
					e[i].push_back( Edge(j, dist) );
					e[j].push_back( Edge(i, dist) );
				}
			}
		}

		cin >> M;
		for(int j = 0; j < M; j++){
			cin >> S >> G; S--; G--;

			priority_queue<Data> pq;
			Data pq_top;
			pq.push( Data(S, 0) );
			double memo[1000];
			fill_n(memo, N, -1);
			bool na = true;

			while( !pq.empty() ){
				pq_top = pq.top(); pq.pop();
			
				if(memo[pq_top.n] > -0.5) continue;
				memo[pq_top.n] = pq_top.cost;
				if(pq_top.n == G){
					na = false; break;
				}

				for(int i = 0; i < e[pq_top.n].size(); i++){
					pq.push( Data( e[pq_top.n][i].to, pq_top.cost + e[pq_top.n][i].cost ) );
				}
			}

			if(na){
				puts("NA"); break;
			}

			stack<int> ans;
			while(true){
				ans.push(G);
				if(G == S) break;
				for(int i = 0; i < e[G].size(); i++){
					if( abs(memo[G] - memo[ e[G][i].to ] - e[G][i].cost) < EPS){
						G = e[G][i].to; break;
					}
				}
			}
		
			printf("%d", ans.top()+1 ); ans.pop();
			while( !ans.empty() ){
				printf(" %d", ans.top()+1 ); ans.pop();
			}puts("");
		}
	}
	return 0;
}